(CNN) Eight years ago, Barack Obama, America's first African-American President, was elected on a vision of hope and change. He told the nation in his first inaugural speech: "There are some who question the scale of our ambitions, who suggest that our system cannot tolerate too many big plans." CNN Opinion's contributors and expert commentators were ready to weigh in.

Here is a selection of op-eds that help tell the tale of Obama's historic two terms in office. The opinions expressed in these commentaries are solely those of the author.

"Today, Barack Obama is hope for a better tomorrow for all Americans. He stands on the shoulders of all those people who have incessantly prayed for a day when 'justice will run down like waters and righteousness as a mighty stream.' "

Watch CNN Films' premiere of its documentary, "The End: Inside the Last Days of the Obama White House," Wed. Jan. 18, at 9p ET on CNN .

----------------

"President-elect Obama faces enormous mountains to climb that will require enormous public support. He will no doubt pursue the policies he considers best for digging our nation out of some deep ditches, both domestically and internationally. ... (T)he style that led him to the White House -- a calm, thoughtful, steady approach to policy combined with an extraordinary capacity to inspire -- is the same style that will make him an extraordinary leader."

---------------

"The President's polling numbers at home are coming in at an impressive rate. A Democracy Corps poll taken this week found that the percentage of likely voters saying the country is going in the right direction is up to 38 percent, the highest level recorded in more than three years."

---------------

"As an American, I am proud when our President does well overseas. Being humble worked much better than being cocky. But in order to lead, you must be tough. Being liked is important. Being respected will be the test. The President had a great opening round, but there are many more rounds to fight."

-----------------

"For both George W. Bush and Obama, catching (Osama) bin Laden was the big prize. Whoever got him would carry a bigger stick. And that's what Obama has just done."

-----------------

Photos: Barack Obama's presidency U.S. President Barack Obama attends the Nuclear Security Summit in the Hague, Netherlands, in March 2014. As Obama's second term nears its close, here's a look at some key moments of his administration. Hide Caption 1 of 55 Photos: Barack Obama's presidency First lady Michelle Obama brushes specks from the coat of then-Sen. Obama in Springfield, Illinois, just before he announced his candidacy for President in February 2007. Their daughters Malia, left, and Sasha wait in the foreground. Hide Caption 2 of 55 Photos: Barack Obama's presidency Obama appears on "Meet the Press" with Tim Russert, right, in Des Moines, Iowa, in November 2007. Hide Caption 3 of 55 Photos: Barack Obama's presidency Obama shakes hands with supporters after addressing a rally in Concord, New Hampshire, in January 2008. Hide Caption 4 of 55 Photos: Barack Obama's presidency Obama gives a speech at the National Constitution Center in Philadelphia in March 2008. Hide Caption 5 of 55 Photos: Barack Obama's presidency Obama speaks at the 2008 Democratic National Convention in Denver. Hide Caption 6 of 55 Photos: Barack Obama's presidency Obama stands on stage in Chicago with his family after winning the presidential election on November 4, 2008. Hide Caption 7 of 55 Photos: Barack Obama's presidency Obama poses in the Oval Office with several former U.S. Presidents in January 2009. From left are George H. W. Bush, Obama, George W. Bush, Bill Clinton and Jimmy Carter. Hide Caption 8 of 55 Photos: Barack Obama's presidency Obama is sworn in by Chief Justice John Roberts as the 44th President of the United States on January 20, 2009. Hide Caption 9 of 55 Photos: Barack Obama's presidency As retired military officers stand behind him, Obama signs an executive order to close down the detention center at Guantanamo Bay, Cuba, in January 2009. Hide Caption 10 of 55 Photos: Barack Obama's presidency Obama and Vice President Joe Biden look at solar panels as they tour the solar array at the Denver Museum of Nature and Science on February 17, 2009. That same day, Obama signed the American Recovery and Reinvestment Act. Hide Caption 11 of 55 Photos: Barack Obama's presidency A soldier hugs Obama during his surprise visit to Camp Victory just outside Baghdad, Iraq, in April 2009. Hide Caption 12 of 55 Photos: Barack Obama's presidency Obama bends over so the son of a White House staff member can pat his head during a visit to the Oval Office in May 2009. The boy wanted to know if Obama's hair felt like his. Hide Caption 13 of 55 Photos: Barack Obama's presidency Obama kisses Sonia Sotomayor's cheek after announcing her as his nominee for Supreme Court justice in May 2009. Hide Caption 14 of 55 Photos: Barack Obama's presidency Palestinian security forces in Jenin, West Bank, listen to Obama speak from Cairo University in Egypt in June 2009. The Palestinian Authority hailed as a "good beginning" Obama's speech to the Muslim world in which he reiterated his support for a Palestinian state. Hide Caption 15 of 55 Photos: Barack Obama's presidency Obama and the first lady meet with Pope Benedict XVI in Vatican City in July 2009. Hide Caption 16 of 55 Photos: Barack Obama's presidency Obama hosts the Apollo 11 astronauts -- from left, Edwin "Buzz" Aldrin, Michael Collins and Neil Armstrong -- in the Oval Office on July 20, 2009. It was the 40th anniversary of the moon landing. Hide Caption 17 of 55 Photos: Barack Obama's presidency Police Sgt. James Crowley, second right, of Cambridge, Massachusetts, speaks with Harvard Professor Henry Louis Gates Jr., second left, alongside Obama and Biden as they share beers on the South Lawn of the White House in July 2009. The so-called Beer Summit was held after Crowley arrested Gates at his own home, which sparked tensions and racial furor. Hide Caption 18 of 55 Photos: Barack Obama's presidency Obama salutes during the transfer of Sgt. Dale R. Griffin at Dover Air Force Base in Dover, Delaware, in October 2009. Obama traveled to the base to meet the plane carrying the bodies of 18 U.S. personnel killed in Afghanistan. Hide Caption 19 of 55 Photos: Barack Obama's presidency Obama walks along the Great Wall of China in November 2009. Hide Caption 20 of 55 Photos: Barack Obama's presidency Obama delivers a speech after receiving the Nobel Peace Prize in Oslo, Norway, in December 2009. Hide Caption 21 of 55 Photos: Barack Obama's presidency Obama and former Presidents Clinton and George W. Bush walk to the White House Rose Garden to speak about relief efforts for earthquake-stricken Haiti in January 2010. Hide Caption 22 of 55 Photos: Barack Obama's presidency First daughters Sasha and Malia Obama play in the snow with their father after a snowstorm hit Washington in February 2010. Hide Caption 23 of 55 Photos: Barack Obama's presidency Obama's signature on the Affordable Care Act is seen at the White House in March 2010. Hide Caption 24 of 55 Photos: Barack Obama's presidency Obama throws out the opening pitch before a baseball game between the Philadelphia Phillies and the Washington Nationals in April 2010. Hide Caption 25 of 55 Photos: Barack Obama's presidency Obama and his daughter Sasha swim in Panama City Beach, Florida, in August 2010, to encourage people to come back to the Gulf Coast after a devastating oil spill. Hide Caption 26 of 55 Photos: Barack Obama's presidency Obama laughs as he makes a statement on his birth certificate in April 2011. Obama said he was amused over conspiracy theories about his birthplace, and he said the media's obsession with the "sideshow" issue was a distraction in a "serious time." Hide Caption 27 of 55 Photos: Barack Obama's presidency Obama, Biden, Secretary of State Hillary Clinton and members of the national security team receive live updates on the mission to capture or kill Osama bin Laden on May 1, 2011. Hide Caption 28 of 55 Photos: Barack Obama's presidency U.S. Marines watch from Afghanistan as Obama announces the death of bin Laden on May 2, 2011. Hide Caption 29 of 55 Photos: Barack Obama's presidency Obama enjoys a pint of Guinness in his ancestral home of Moneygall, Ireland, in May 2011. Hide Caption 30 of 55 Photos: Barack Obama's presidency Obama and the first lady meet with Britain's Prince William and Catherine, Duchess of Cambridge, at Buckingham Palace in May 2011. Hide Caption 31 of 55 Photos: Barack Obama's presidency Obama and Missouri Gov. Jay Nixon walk together in May 2011 during a tour of the tornado devastation in Joplin, Missouri. Hide Caption 32 of 55 Photos: Barack Obama's presidency Obama delivers remarks to troops and military families at Fort Bragg, North Carolina, on December 14, 2011, marking the exit of U.S. soldiers from Iraq. Hide Caption 33 of 55 Photos: Barack Obama's presidency Obama pays for a dog toy as he shops with his dog Bo at a PetSmart in Alexandria, Virginia, in December 2011. Hide Caption 34 of 55 Photos: Barack Obama's presidency Obama sits on the famed Rosa Parks bus at the Henry Ford Museum in Dearborn, Michigan, in April 2012. Hide Caption 35 of 55 Photos: Barack Obama's presidency British Prime Minister David Cameron, Obama, German Chancellor Angela Merkel and others watch the overtime shootout of the Champions League final between Chelsea and Bayern Munich in a conference room at Camp David, Maryland, during a G-8 Summit in May 2012. Hide Caption 36 of 55 Photos: Barack Obama's presidency Obama sits in his chair during a Cabinet meeting in July 2012. This image was tweeted by his official Twitter account in August 2012 in response to Clint Eastwood's "empty chair" speech at the Republican National Convention. The tweet simply said, "This seat's taken." Hide Caption 37 of 55 Photos: Barack Obama's presidency Obama casts a shadow in this picture as he accepts the 2012 Democratic nomination for President during the final day of the Democratic National Convention in September 2012. Hide Caption 38 of 55 Photos: Barack Obama's presidency Obama and Republican presidential candidate Mitt Romney participate in the first presidential debate of the 2012 election. Hide Caption 39 of 55 Photos: Barack Obama's presidency Obama celebrates on stage in Chicago after defeating Romney on Election Day in 2012. Hide Caption 40 of 55 Photos: Barack Obama's presidency Obama pauses during his speech at a memorial service for the victims of the Sandy Hook Elementary School massacre in December 2012. Hide Caption 41 of 55 Photos: Barack Obama's presidency Hundreds of thousands gather at the U.S. Capitol building as Obama is inaugurated for his second term on January 21, 2013. Hide Caption 42 of 55 Photos: Barack Obama's presidency Israeli President Shimon Peres, left, and Prime Minister Benjamin Netanyahu, right, stand with Obama after Obama arrived in Tel Aviv, Israel, in March 2013. Hide Caption 43 of 55 Photos: Barack Obama's presidency Obama adjusts an umbrella held by a Marine during a White House news conference with Turkish Prime Minister Recep Tayyip Erdogan in May 2013. Hide Caption 44 of 55 Photos: Barack Obama's presidency Jay Leno interviews Obama on "The Tonight Show" in August 2013. Hide Caption 45 of 55 Photos: Barack Obama's presidency White House press secretary Jay Carney fields questions from reporters during a daily press briefing at the White House in September 2013. Obama had just pushed for congressional approval for limited military strikes against the Syrian government. Hide Caption 46 of 55 Photos: Barack Obama's presidency Actor and comedian Zach Galifianakis interviews Obama during his appearance on "Between Two Ferns," a digital video series with a laser focus on reaching people aged 18 to 34. The President urged young people to sign up for his new health care plan in the video posted on the website Funny or Die. Hide Caption 47 of 55 Photos: Barack Obama's presidency Obama walks to the Oval Office on August 7, 2014, the same day he announced the beginning of airstrikes on ISIS. Hide Caption 48 of 55 Photos: Barack Obama's presidency Obama speaks to the nation about normalizing diplomatic relations with Cuba in December 2014. Hide Caption 49 of 55 Photos: Barack Obama's presidency From left, House Majority Leader Kevin McCarthy, House Minority Leader Nancy Pelosi and House Speaker John Boehner listen as Obama speaks during a meeting in the Cabinet Room of the White House on January 13, 2015. Hide Caption 50 of 55 Photos: Barack Obama's presidency Obama responds to a heckler who interrupted his speech during a White House reception for LGBT Pride Month in June 2015. Hide Caption 51 of 55 Photos: Barack Obama's presidency Obama cries in January 2016 as he delivers a statement on his executive action to reduce gun violence. Hide Caption 52 of 55 Photos: Barack Obama's presidency Cuban President Raul Castro tries to lift up Obama's arm at the end of a joint news conference in Havana, Cuba, in March 2016. Castro hailed Obama's opposition to a long-standing economic "blockade," but said it would need to end before ties between the two countries are fully normalized. Hide Caption 53 of 55 Photos: Barack Obama's presidency Obama visits Prince William, Duchess Catherine and their son, Prince George, during a trip to London in April 2016. Hide Caption 54 of 55 Photos: Barack Obama's presidency Obama hugs Hillary Clinton after speaking at the Democratic National Convention in July 2016. Obama told the crowd at Philadelphia's Wells Fargo Center that Clinton is ready to be commander in chief. "For four years, I had a front-row seat to her intelligence, her judgment and her discipline," he said, referring to Clinton's stint as secretary of state. Hide Caption 55 of 55

"Obama has lost his way so badly that even his core liberal supporters should be questioning whether they have got the right man in the job."

-----------------

"A wise executive -- in a school, a business or a nation -- must help his or her team learn to respect all styles of self-presentation and to listen to all views, as Obama evidently did when it was brought to his attention."

-----------------

"I knew how serious this problem is. Nearly one in three of our children are overweight or obese, at risk for illnesses such as diabetes, heart disease and cancer that cost our economy billions of dollars each year to treat. I also knew the conventional wisdom on this issue. ..."

-----------------

"At 8:20 Friday morning, in the White House Diplomatic Reception Room, Obama gathered some of his top aides around him and said simply, 'I've considered the decision: It's a go.'... If you still think this was an easy call, I have a compound in Abbottabad I'd like to sell to you."

----------------

"When a president who wants to be transformational runs a campaign that wants to deliver transparent caricatures, there's a downside. The candidate starts looking like all the other pols."

--------------

"You may believe that we, as a country, shouldn't pay for care for the uninsured. But most of us are unwilling to let the sick, especially children, suffer. So we -- individual Americans -- have been paying for this health care, saving those companies money, regardless of whether we availed ourselves of their services. No longer. Under the Affordable Care Act, those costs will be the responsibility of those businesses and eventually their customers."

---------------

"Some 2.6 million men and woman answered the call to serve in Iraq and Afghanistan. But now, a decade later, President Barack Obama is not answering their calls for help. And the public still doesn't seem to get it."

-----------------

Photos: Michelle Obama's 'Let's Move!' program Michelle Obama's 'Let's Move!' program – In 2010, first lady Michelle Obama started Let's Move!, an initiative to address childhood obesity and help all our kids grow up healthy. Here she participates in musical activities with students in an event at Orr Elementary School in Washington in 2013. Hide Caption 1 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – The theme for the fifth year anniversary of Let's Move! is: Celebrate, challenge, champion. The first lady joins in at the Healthy Kids Fair on the South Lawn of the White House in 2009. Hide Caption 2 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – Across America, cities, towns and counties are supporting healthy afters-school programs and youth sports leagues. Here kids attend a Let's Move! event at Woldenberg Park in New Orleans in 2010.

Hide Caption 3 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – Through the initiative, millions of kids are attending healthier day care centers, where fruits and vegetables have replaced cookies and juice. Michelle Obama speaks at a Let's Move! Walmart announcement at The Arc in Washington in 2010. Hide Caption 4 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – Nearly 9 million kids participate in the Let's Move! Active Schools program and get 60 minutes of physical activity a day. Nearly 5 million kids will be attending healthier after-school programs in the next five years. The first lady meets with students in New Hampshire Estates Elementary School in Silver Spring, Maryland, in 2010.

Hide Caption 5 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – The first lady speaks about Let's Move! at the Visitors Center in Red Rock Canyon, Nevada, in 2010. Hide Caption 6 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – Childhood obesity rates have finally stopped rising -- and obesity rates are actually falling among our youngest children, according to Let's Move! initiative. The first lady attends the White House Kitchen Garden harvest on the South Lawn in 2010. Hide Caption 7 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – While Let's Move! has made strides in helping kids become healthy, the statistics are still daunting. Here she attends a partnership event with Chicago Blackhawks and Washington Capitals players on the South Lawn of the White House in 2011. Hide Caption 8 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – First lady Michelle Obama and Ellen DeGeneres dance during a taping of "The Ellen DeGeneres Show" marking the second anniversary of Let's Move! in Burbank, California, in 2012. Hide Caption 9 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – America still spends nearly $200 billion a year on obesity-related health care costs, and that figure will jump to nearly $350 billion a year by 2018, according to Let's Move! campaign. Michelle Obama visits the Fresh Grocer store in Philadelphia in 2010. Hide Caption 10 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – The first lady attends a chef's demonstration with third-grade students from Pocantico Hill School and John F. Kennedy Magnet School, before a luncheon at Blue Hill Farm in Pocantico Hills, New York, in 2010. Hide Caption 11 of 12 Photos: Michelle Obama's 'Let's Move!' program MIchelle Obama's 'Let's Move!' program – First lady says she is committed to giving kids the healthy futures they deserve. Here she works with chefs and students in the White House Kitchen Garden on the South Lawn in 2010. Hide Caption 12 of 12

"Obama's humor is often delivered the way a comedian dealing with a heckler would do it. He tries to undermine his opponents with it and get the crowd -- in this case the public -- on his side."

--------------

"It's impossible to believe that anyone could seriously call President Obama a chauvinist over this banter between friends. No matter your politics, you will have a hard time finding a president who has included women more in his agenda. What has he done for us lately? Let me recall just a few things. ...

--------------

"The other, more troubling possibility is that the President surrendered to his political instincts. He wants disadvantaged Americans to believe that he and his family are one of them -- despite their life of unparalleled privilege -- and he wanted the prosecutors, judge and jury to believe that this was a case about race where justice demanded a guilty verdict."

--------------

"Obama doesn't want to be responsible for the red lines he set either, apparently. He insisted that when it came to (Bashar) al-Assad's use of chemical weapons, 'I didn't set a red line; the world set a red line.' "

---------------

"Others will accuse Obama of promoting division by using the office to highlight the issues of minorities over those of their white counterparts. As if one in three black males being projected to go to prison at some point in their lives can be construed as some sort of highlight. But such is the world of the first black President of these United States."

---------------

"This is the new, all-drama Obama. And all of that pent-up energy, ambition and action, barely two months after losing control of the Senate. 'Anyone would become annoyed and frustrated if you were accused of being a wuss,' says a senior Democratic policy adviser. 'And it's always better to be on offense than defense.' "

---------------

"I find it hard to believe that collectively President Obama, Vice President Joe Biden, Secretary of State John Kerry, Secretary of Defense Chuck Hagel, Treasury Secretary Jack Lew and Attorney General Eric Holder -- who was actually in France that day for a conference on counterterrorism -- just had no time in their schedules on Sunday."

---------------

"You have mounting pressure on President Obama from an increasingly frustrated Latino community and Democratic base. He made pie-in-the-sky campaign promises offering immigration reform in his first year in office. In his first two years, he had a Democratic Senate and Democratic House. He had the chance to act. Instead, he sat on his hands as the problem continued to fester."

---------------

"After traveling the world as first lady and meeting so many girls like Raphina and Rihab, I carry their hopes and their ambitions with me everywhere I go, and I plan to continue my work on their behalf not just for my final seven months as first lady, but for the rest of my life. I hope you will join me in this mission."

---------------

"We are so accustomed to gun violence that we have become inured to it -- numb. It's easier. The President cried because he allowed himself to feel something no one wants to feel: the tremendous pain of losing someone you love, the shame of knowing you did nothing to prevent it and the relief that overcomes you when you commit to changing."

----------------

"Obama even has the cheek to blame Europe for Libya's descent into chaos following the 2011 Western intervention. Obama did not want to get involved in another Middle East war. He encouraged Britain and France to take the lead."

----------------

"We have set a clear goal vital to the next chapter of America's story in space: sending humans to Mars by the 2030s and returning them safely to Earth, with the ultimate ambition to one day remain there for an extended time."

---------------

"Obama has left an indelible mark. He and his family occupied the White House with dignity, grace and good humor. He ran an administration that was largely scandal-free. He celebrated and promoted American excellence in every sphere, from science to art to sports. And he did it all while under a microscope, because he looked different."