(CNN) Former Colorado Gov. John Hickenlooper ended his bid for the 2020 Democratic presidential nomination on Thursday, releasing a video in which he nodded at the possibility of a future Senate run .

The announcement comes after three Democrats familiar with the matter told CNN on Wednesday that Hickenlooper was poised to drop out .

"Today, I'm ending my campaign for President," Hicklenlooper said in the three-minute video. "But I will never stop believing that America can only move forward when we work together."

He added: "A little over six months ago, I announced my run for President. In almost every aspect, this journey has been more exciting and more rewarding than I ever imagined. Although, of course, I did imagine a very different conclusion."

Hickenlooper, who struggled to break out of the crowded field of candidates, has not yet decided whether he will run for the Senate as party leaders have urged him to do, sources said. He did not make an announcement on that decision in the Thursday video, but acknowledged the possibility.

"People want to know what comes next for me. I've heard from so many Coloradans who want me to run for the United States Senate. They remind me how much is at stake for our country. And our state. I intend to give that some serious thought," the governor said. "I've been a geologist, a small businessman, a mayor, a governor and a candidate for president of the United States. At each step, I've always looked forward with hope. And I always will."

Hickenlooper's exit from the race leaves 23 other Democrats vying for the 2020 nomination.

Photos: Former presidential candidate John Hickenlooper Photos: Former presidential candidate John Hickenlooper Former Colorado Gov. John Hickenlooper attends the National Action Network convention in April 2019. He announced a month earlier that he would be running for president. Hide Caption 1 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper is joined by his first wife, Helen, and their son, Teddy, as he announces his plans to run for mayor of Denver in January 2003. Hide Caption 2 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper celebrates after winning the mayoral race in June 2003. Hide Caption 3 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper makes final preparations for his State of the City address in July 2004. Hide Caption 4 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper and the mayors of Lakewood and Aurora, Colorado, compete in a 20-yard dash to promote the Colorado Colfax Marathon in April 2006. Hide Caption 5 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper is sworn in for his second term as mayor in July 2007. Hide Caption 6 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper jokes around as the Denver Museum of Nature and Science unveils new solar panels in June 2008. Hide Caption 7 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper is greeted by Gidget, a sea lion at the Denver Zoo, in March 2009. Hide Caption 8 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper uses a bicycle to power a blender while visiting a Girls Inc. booth in June 2009. Hide Caption 9 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper speaks at an election-night party after he was elected governor of Colorado in November 2010. Hide Caption 10 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper gives the "all aboard" call just before a train departs Denver in July 2011. Hide Caption 11 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper attends a Thanksgiving banquet at the Denver Rescue Mission in November 2011. Hide Caption 12 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper is briefed on wildfire damage in March 2012. Hide Caption 13 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper bows his head while speaking at a vigil held for victims of a mall shooting in Aurora, Colorado, in July 2012. Hide Caption 14 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper speaks at the Democratic National Convention in September 2012. Hide Caption 15 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper is interviewed in Denver in July 2014. Hide Caption 16 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper shares a beer with President Barack Obama while Obama was in Denver in July 2014. Hide Caption 17 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper plays the banjo in July 2014 while performing with Ketch Secor of Old Crow Medicine Show. Hide Caption 18 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper has a quiet moment in his office between daily meetings in September 2014. Hide Caption 19 of 30 Photos: Former presidential candidate John Hickenlooper With his son by his side, Hickenlooper takes the oath of office for his second term as governor. Hickenlooper and his first wife, Helen, separated in 2012 and divorced in 2015. Hide Caption 20 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper delivers remarks at the White House during the 2015 Governors Dinner. Hide Caption 21 of 30 Photos: Former presidential candidate John Hickenlooper Legislators surprise Hickenlooper and his fiancee, Robin Pringle, throwing rice on the couple after his State of the State address in January 2016. They were married two days later. Hide Caption 22 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper and Democratic presidential candidate Hillary Clinton wave to supporters after her speech at Adams City High School in Commerce City, Colorado, in August 2016. Hide Caption 23 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper rappels down a Denver skyscraper for a fundraiser in September 2016. Hide Caption 24 of 30 Photos: Former presidential candidate John Hickenlooper With his governorship drawing to a close, term-limited Hickenlooper speaks to the media on Election Day in 2018. Hide Caption 25 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper is joined by his wife, Robin, and his son, Teddy, before the inauguration of his successor, Jared Polis, in January 2019. Hide Caption 26 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper speaks to supporters at his campaign kickoff rally in Denver in March 2019. Hide Caption 27 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper addresses a crowd in Atlanta at his CNN town hall in March 2019. Hide Caption 28 of 30 Photos: Former presidential candidate John Hickenlooper During the CNN Democratic debates in July 2019, Hickenlooper called out US Sen. Bernie Sanders for throwing up his hands. Hide Caption 29 of 30 Photos: Former presidential candidate John Hickenlooper Hickenlooper and US Sen. Kirsten Gillibrand flip pork chops at the Iowa State Fair in August 2019. Hide Caption 30 of 30

Hickenlooper framed his candidacy around stemming the leftward lurch of the Democratic Party. The two-term Colorado governor was a moderate voice in the primary, making his opposition to democratic socialism-- including Vermont Sen. Bernie Sanders' political philosophy -- central to his campaign.

But that strategy failed to gain traction and Hickenlooper's campaign lost three of its most senior staffers in early July, including Brad Komar, the campaign manager. The losses signaled to many Democrats that Hickenlooper's campaign was on its last legs, but Democrats close to the governor said he wanted to stay in and reassess his chances after CNN's debate in late July

Following that debate, it appeared the former Denver mayor would struggle to make the stage in the next round of debates in September as he was behind on both the fundraising and polling thresholds for qualification.

Hickenlooper's exit now opens the possibility that the once popular governor could run for Senate in Colorado, challenging Sen. Cory Gardner, a Republican seen as one of the most vulnerable lawmakers in 2020.

Hickenlooper spoke with Senate Minority Leader Chuck Schumer of New York about potentially challenging Gardner following the July debate. He pressed ahead with his presidential campaign following that conversation, visiting the Iowa State Fair in Des Moines this past weekend along with many of the other presidential candidates.

Hickenlooper faces two issues in a Senate run, though: The governor has lambasted the prospect of running for Senate and Democratic Colorado Senate candidate Mike Johnston raised more in the second quarter of 2019 than Hickenlooper raised for his presidential bid.

The former governor spent the first few months of his presidential campaign knocking the idea of him jumping into the Senate race.

"If the Senate is so good, how come all of those senators are trying to get out?" Hickenlooper told CNN earlier this year, a nod to the number of Democratic senators who are running for president.

"The Senate doesn't attract me," he said. "It just doesn't attract me."

But by last weekend, with his presidential campaign nearing an end, he told CNN, "I don't rule anything out."

Even in a crowded Democratic primary, Hickenlooper is still seen as the party's strongest candidate to take on Gardner. Curtis Hubbard, a Democratic strategist for a firm that has worked for Hickenlooper in the past, has recently registered domain names like Hick4Senate.com in the hope that the former governor switches races.