This is the first of a two-part series looking at the path to victory for Donald Trump and Hillary Clinton. Click here for the second story: How Hillary Clinton could win.

(CNN) Donald Trump is aiming to pull off one of the greatest political comebacks in history.

The Republican nominee is rebounding from a summer of repeated stumbles that threatened to undermine his candidacy, underscoring his ability to claw his way back and stay competitive despite controversies that would sink any other politician.

Trump and Hillary Clinton enter the critical post-Labor Day phase of the campaign in a dead heat. A CNN/ORC national poll released Tuesday finds Trump ahead of Clinton by two points -- 45% to 43% -- among likely voters. The race is also tight among registered voters, where Clinton has a three point advantage. Both findings are within the margin of error.

The narrowing of the race is a remarkable feat for Trump, who was down 10 points a month ago in CNN's Poll of Polls

Trump still faces serious hurdles that strong poll numbers can't mask. He's alienated much of the electorate, especially minorities who showed up in droves over the past two cycles to support Barack Obama. He's doing poorly among college-educated women, who are typically a Republican stronghold, and his rudimentary organization is dwarfed by Clinton's political machine in swing states where he still lags in most polls.

Narrow path to the White House

But if Trump can spend the next 63 days shining a relentless and unforgiving spotlight on Clinton's vulnerabilities and avoid more self-inflicted wounds, there could be a path -- however narrow -- for him to reach the White House.

"Can he fundamentally alter the focus of this election right now — which is on him?" asked Bill Lacy, a GOP veteran who ran presidential campaigns for Bob Dole and Fred Thompson. "He needs to make this election about Secretary Clinton."

Photos: Donald Trump's rise Photos: Donald Trump's rise President-elect Donald Trump has been in the spotlight for years. From developing real estate and producing and starring in TV shows, he became a celebrity long before winning the White House. Hide Caption 1 of 37 Photos: Donald Trump's rise Trump at age 4. He was born in 1946 to Fred and Mary Trump in New York City. His father was a real estate developer. Hide Caption 2 of 37 Photos: Donald Trump's rise Trump, left, in a family photo. He was the second-youngest of five children. Hide Caption 3 of 37 Photos: Donald Trump's rise Trump, center, stands at attention during his senior year at the New York Military Academy in 1964. Hide Caption 4 of 37 Photos: Donald Trump's rise Trump, center, wears a baseball uniform at the New York Military Academy in 1964. After he graduated from the boarding school, he went to college. He started at Fordham University before transferring and later graduating from the Wharton School, the University of Pennsylvania's business school. Hide Caption 5 of 37 Photos: Donald Trump's rise Trump stands with Alfred Eisenpreis, New York's economic development administrator, in 1976 while they look at a sketch of a new 1,400-room renovation project of the Commodore Hotel. After graduating college in 1968, Trump worked with his father on developments in Queens and Brooklyn before purchasing or building multiple properties in New York and Atlantic City, New Jersey. Those properties included Trump Tower in New York and Trump Plaza and multiple casinos in Atlantic City. Hide Caption 6 of 37 Photos: Donald Trump's rise Trump attends an event to mark the start of construction of the New York Convention Center in 1979. Hide Caption 7 of 37 Photos: Donald Trump's rise Trump wears a hard hat at the Trump Tower construction site in New York in 1980. Hide Caption 8 of 37 Photos: Donald Trump's rise Trump was married to Ivana Zelnicek Trump from 1977 to 1990, when they divorced. They had three children together: Donald Jr., Ivanka and Eric. Hide Caption 9 of 37 Photos: Donald Trump's rise The Trump family, circa 1986. Hide Caption 10 of 37 Photos: Donald Trump's rise Trump uses his personal helicopter to get around New York in 1987. Hide Caption 11 of 37 Photos: Donald Trump's rise Trump stands in the atrium of the Trump Tower. Hide Caption 12 of 37 Photos: Donald Trump's rise Trump attends the opening of his new Atlantic City casino, the Taj Mahal, in 1989. Hide Caption 13 of 37 Photos: Donald Trump's rise Trump signs his second book, "Trump: Surviving at the Top," in 1990. Trump has published at least 16 other books, including "The Art of the Deal" and "The America We Deserve." Hide Caption 14 of 37 Photos: Donald Trump's rise Trump and singer Michael Jackson pose for a photo before traveling to visit Ryan White, a young child with AIDS, in 1990. Hide Caption 15 of 37 Photos: Donald Trump's rise Trump dips his second wife, Marla Maples, after the couple married in a private ceremony in New York in December 1993. The couple divorced in 1999 and had one daughter together, Tiffany. Hide Caption 16 of 37 Photos: Donald Trump's rise Trump putts a golf ball in his New York office in 1998. Hide Caption 17 of 37 Photos: Donald Trump's rise An advertisement for the television show "The Apprentice" hangs at Trump Tower in 2004. The show launched in January of that year. In January 2008, the show returned as "Celebrity Apprentice." Hide Caption 18 of 37 Photos: Donald Trump's rise A 12-inch talking Trump doll is on display at a toy store in New York in September 2004. Hide Caption 19 of 37 Photos: Donald Trump's rise Trump attends a news conference in 2005 that announced the establishment of Trump University. From 2005 until it closed in 2010, Trump University had about 10,000 people sign up for a program that promised success in real estate. Three separate lawsuits -- two class-action suits filed in California and one filed by New York's attorney general -- argued that the program was mired in fraud and deception. Trump's camp rejected the suits' claims as "baseless." And Trump has charged that the New York case against him is politically motivated. Hide Caption 20 of 37 Photos: Donald Trump's rise Trump attends the U.S. Open tennis tournament with his third wife, Melania Knauss-Trump, and their son, Barron, in 2006. Trump and Knauss married in 2005. Hide Caption 21 of 37 Photos: Donald Trump's rise Trump wrestles with "Stone Cold" Steve Austin at WrestleMania in 2007. Trump has close ties with the WWE and its CEO, Vince McMahon. Hide Caption 22 of 37 Photos: Donald Trump's rise For "The Apprentice," Trump was honored with a star on the Hollywood Walk of Fame in January 2007. Hide Caption 23 of 37 Photos: Donald Trump's rise Trump appears on the set of "The Celebrity Apprentice" with two of his children -- Donald Jr. and Ivanka -- in 2009. Hide Caption 24 of 37 Photos: Donald Trump's rise Trump poses with Miss Universe contestants in 2011. Trump had been executive producer of the Miss Universe, Miss USA and Miss Teen USA pageants since 1996. Hide Caption 25 of 37 Photos: Donald Trump's rise In 2012, Trump announces his endorsement of Republican presidential candidate Mitt Romney. Hide Caption 26 of 37 Photos: Donald Trump's rise Trump speaks in Sarasota, Florida, after accepting the Statesman of the Year Award at the Sarasota GOP dinner in August 2012. It was shortly before the Republican National Convention in nearby Tampa. Hide Caption 27 of 37 Photos: Donald Trump's rise Trump appears on stage with singer Nick Jonas and television personality Giuliana Rancic during the 2013 Miss USA pageant. Hide Caption 28 of 37 Photos: Donald Trump's rise In June 2015, during a speech from Trump Tower, Trump announced that he was running for President. He said he would give up "The Apprentice" to run. Hide Caption 29 of 37 Photos: Donald Trump's rise Trump -- flanked by U.S. Sens. Marco Rubio, left, and Ted Cruz -- speaks during a CNN debate in Miami on March 10. Trump dominated the GOP primaries and emerged as the presumptive nominee in May. Hide Caption 30 of 37 Photos: Donald Trump's rise The Trump family poses for a photo in New York in April. Hide Caption 31 of 37 Photos: Donald Trump's rise Trump speaks during a campaign event in Evansville, Indiana, on April 28. After Trump won the Indiana primary, his last two competitors dropped out of the GOP race. Hide Caption 32 of 37 Photos: Donald Trump's rise Trump delivers a speech at the Republican National Convention in July, accepting the party's nomination for President. "I have had a truly great life in business," he said. "But now, my sole and exclusive mission is to go to work for our country -- to go to work for you. It's time to deliver a victory for the American people." Hide Caption 33 of 37 Photos: Donald Trump's rise Trump faces Democratic nominee Hillary Clinton in the first presidential debate, which took place in Hempstead, New York, in September. Hide Caption 34 of 37 Photos: Donald Trump's rise Trump apologizes in a video, posted to his Twitter account in October, for vulgar and sexually aggressive remarks he made a decade ago regarding women. "I said it, I was wrong and I apologize," Trump said, referring to lewd comments he made during a previously unaired taping of "Access Hollywood." Multiple Republican leaders rescinded their endorsements of Trump after the footage was released. Hide Caption 35 of 37 Photos: Donald Trump's rise Trump walks on stage with his family after he was declared the election winner on November 9. "Ours was not a campaign, but rather, an incredible and great movement," he told his supporters in New York. Hide Caption 36 of 37 Photos: Donald Trump's rise Trump is joined by his family as he is sworn in as President on January 20. Hide Caption 37 of 37

Trump's best chance for altering the race lies in the presidential debates, which begin September 26 and will serve as critical tests of his temperament and knowledge. In front of a vast television audience, the GOP nominee could reshape perceptions of his character and readiness -- if he can avoid being drawn into gaffes and personality clashes by Clinton.

He will benefit from rock-bottom expectations, given controversies whipped up by his tempestuous personality and the vast gulf in experience between Trump and Clinton.

But the formal one-on-one presidential debates -- which personify the "commander-in-chief test" many Americans ponder as they select their next president -- are a far stiffer test for Trump than the crowded free-for-alls of the Republican primary race.

There will be no space for the billionaire to relax and regenerate his energy while rivals spar or networks cut to commercial breaks. The intensity of the questioning and his confrontation with a prepared and experienced candidate like Clinton will leave no place to hide.

Still, there is much for him to gain in the three scheduled televised showdowns and he will get an unfiltered chance to raise Clinton's political vulnerabilities before the American people.

Clinton's liabilities

Those liabilities, and the historic challenge Clinton faces in seeking a third consecutive White House term for her party and the nation's sour political mood, also help explain why Trump is still alive.

In recent weeks, the Democratic nominee has yet again been hounded by the controversy over the private email server that has revived questions about her character and honesty. Her campaign has also been forced to deny claims of influence peddling between her family's philanthropic Clinton Foundation and the State Department while she ran US diplomacy.

In an interview Monday with CNN's Jeff Zeleny, Vice President Joe Biden acknowledged Clinton's struggles with questions about honesty.

"The truth is Hillary knows it's a problem and she's trying to figure out how to remedy it," Biden said. "My advice to her: The best way to remedy it is to talk about what you care about and talk about it with some passion and people will see through it."

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For his part, Trump needs to do more than simply disqualify Clinton. He must show he's ready to lead the nation.

To mount an authentic comeback, Trump must finally forge an emotional connection with voters outside his natural base, who have yet to embrace his vision of a nation under siege from terror and crime.

"His appeal to the base Republican vote that won him the nomination in effect has turned many swing voters and Democratic voters against him," said Lacy. "He has to address it by being presidential and doing so constantly."

The Clinton campaign doubts Trump has it in him.

"He would have to do things in the last eight weeks that he appears to have been incapable of doing in the last 16 months," said Clinton's chief strategist Joel Benenson, citing Trump's need to build a ground game, court swing voters and improve his appeal to suburban women.

Clinton is banking on a huge turnout from minority voters who helped Obama win the presidency in 2008 and 2012. So far, Trump's attempts to improve his paltry standing among voters who are suspicious of him has been halting and awkward.

Last week, for instance, his trip to Mexico had clear presidential overtones. But hours later, he delivered an angry speech on immigration that further alienated Latino voters and prompted some Latino GOP leaders to take back their endorsement of Trump. And on Monday, he refused to rule out granting legal status to undocumented immigrants.

And on Saturday, Trump met an African-American congregation in Detroit in a bid to counter claims he is a racist. He was politely received but didn't seem to change many minds, according to interviews by CNN afterward.

Still, signs of life in Trump's polling and his energetic performance last week cheer some GOP operatives.

'The wind is at our back'

"It's not just the crowd size, and the enthusiasm and the rallies, but it's (that) all of these polls are now closing in major ways," Republican National Committee Chief Strategist Sean Spicer told CNN. "Look at the wind right now ... the wind is at our back."

Still, Trump has fewer routes than Clinton to the 270 electoral votes needed to win the presidency.

He must start by taking solid red states such as Arizona and Georgia, where Clinton is unusually competitive, off the table. He must also lock down North Carolina, a swing state in recent elections without which he may lack a credible route to 270 electoral votes.

Then Trump must close in on Clinton in all the swing states, in Iowa and Virginia and New Hampshire, as well as Ohio and Florida.

Then, to win a narrow victory in the electoral college, Trump must turn at least one state that went for President Barack Obama in 2012.

Possible candidates include Pennsylvania, where he currently trails Clinton by between three and nine points in polls released over the past month. Another possible target is Michigan, where recent polls have Clinton up by 11 points.

Pennsylvania is a must-win for Trump. If Clinton adds just the Keystone state and Virginia -- home to her running mate, Tim Kaine -- to states considered solidly Democratic, she will be only 10 electoral votes short of the presidency. That will happen even if Trump wins perennial bellwethers Ohio and Florida.

A recent Pennsylvania poll by Monmouth University shows Trump is dangerously weak in the populous Philadelphia suburbs that are often decisive -- a position he must address if he is to compete in the state. Clinton leads 62% to 29% in seven congressional districts around Philadelphia, an area that typically accounts for 40% of statewide turnout. Obama won the region 62% to 37% over Republican Mitt Romney in 2012.

Trump does better than Romney in less populous and diverse western and central Pennsylvania -- but not by enough to make up for his deficit around Philadelphia. He also trails Clinton among white voters with a college degree by 10 points. Romney won that subset by 15 points in 2012.

Unless Trump can turn those voters around, his hopes in Pennsylvania, and in key suburban districts in other swing states such as Columbus, Ohio, look remote.

Alienating moderate Republicans

That's why it surprised many analysts when Trump ditched a plan to soften the hardline on immigration that alienated many moderate white Republicans.

According to CNN exit polls of the Republican primary in Pennsylvania, only 12% of voters said immigration was the most important issue to them. But 60% of Trump voters said it was -- suggesting that the billionaire's position on the issue locks in his base but hurts him among less ideological Republican voters.

Trump's fiery immigration speech last week suggested he has given up on broadening his coalition and instead is betting that the pool of voters marginalized by globalization and the loss of blue-collar jobs is much larger than pollsters believe.

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"This speech is directed at those people living in Ohio, who have thought for whatever reason that their country is not what it was when they grew up," Trump's former campaign manager Corey Lewandowski told CNN after his immigration speech last week.

Trump supporters are also predicting that Democrats have underestimated the size of the GOP nominee's support.

"There's a factor in this election that the media is just ignoring and that is that Hillary Clinton is the most unlikeable person who has ever run for office. Her support is ten miles wide and a half of an inch thick," said Wayne Allyn Root, a conservative commentator from Nevada and author of the recently published "Angry White Male." "I think Hillary Clinton's number of voters will be down 30% versus Obama's four years ago, and I think Trump's share of the white electorate will be up dramatically. He'll gain 4 million extra votes, most of them (from) the white community."

Trump's best bet may be to target the Rust Belt where his anti-trade rhetoric resonates.

Kathleen Hartnett White, a member of Trump's economic advisory council, says the billionaire should relentlessly stress growth, expanding energy production and the slashing of regulations.

"I hope after Labor Day, and I think that is a good day to pivot, that these should be issues in those Rust Belt states," she said. "I would reiterate them over and over again."

October surprise

If all else fails, Trump could benefit from an October surprise.

A stunning news event, such as a terror attack at home or abroad, could prompt some fearful voters to fully embrace Trump's call for curbs on Muslim immigration and warnings that Clinton just does not understand the scale of the threats facing Americans.

Or a sudden global crisis, economic shock -- or even a smoking gun suggesting a hidden Clinton scandal -- could also shake up the race.

Unless he starts making headway soon, with early voting only weeks away, it may take something that jarring for Trump to win. And it's always possible that Trump has already sown the seeds of his own defeat simply by alienating so many voters on the way to the Republican nomination.

"Even if they ran a miracle comeback campaign," Lacy said, "at this point I honestly don't know if it is starting soon enough."