Former Colorado Gov. John Hickenlooper announced Thursday that he ended his run for the 2020 presidential nomination and is giving "serious thought" to running for the U.S. Senate in his home state.

Hickenlooper had struggled to meet the donor and polling thresholds set by the Democratic National Committee to qualify for the debate in September in Houston and was unlikely to make the stage.

Democratic party leaders, including Senate Minority Leader Charles Schumer, pushed for him to take a shot at unseating Colorado Sen. Cory Gardner, one the GOP's vulnerable incumbents up for reelection in 2020.

After months of resisting the Senate entreaties, Hickenlooper said he's opening to the possibility.

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

Hickenlooper had pushed back against the notion that the party needed him in the Senate race, where a large field of high-profile Colorado Democrats had already announced their candidacy.

“There are several other top-flight candidates running for Senate in Colorado, I think any one of which could beat Cory Gardner,” Hickenlooper said during a campaign stop in Iowa last month. “I mean, he is amazingly vulnerable.”

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Hickenlooper entered the Democratic primary March 4 and raised $1 million in the 48 hours that followed. After a lackluster performance in the debates in June in Miami, his campaign showed signs of cracking.

This summer, Hickenlooper confirmed that some of his aides urged him to withdraw from the presidential race and run for Colorado’s U.S. Senate seat or pursue other opportunities. At least six Hickenlooper staffers bailed on the campaign in late June and early July.

If Hickenlooper entered the Senate primary, he could start with a substantial polling lead over the 11 other declared Democratic candidates, according to polling conducted by "a national Democratic group involved in Senate races" and published Monday by The Denver Post.

Hickenlooper entering the Senate race would be a big win for Schumer, who has struggled to persuade high-profile Democrats to take a shot at the Senate.

Democratic presidential hopefuls Montana Gov. Steve Bullock and former Rep. Beto O’Rourke of Texas are languishing in their bids for the White House. Like Hickenlooper, both are seen by party leaders and Democratic voters as attractive candidates to take on incumbent Senate Republicans in their home states.

Bullock and O'Rourke have resisted calls to run for the Senate.

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Before running for president, Hickenlooper served as mayor of Denver from 2003 to 2011, then was elected governor of Colorado, where he served from 2011 to 2019. Rep. Eric Swalwell, D-Calif., dropped out of the presidential race in June.

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As a presidential candidate, Hickenlooper staked his claim as one of the more moderate candidates.

Though he supported comprehensive national health care, he did not endorse the "Medicare for All" plans other candidates proposed. California Democrats booed him in June when he told them “socialism is not the answer” at the Democratic Party State Convention.

"My point that I was trying to make is that the Republicans are going to try to define us," Hickenlooper told USA TODAY after his tough reception at the California convention. "Any large expansion of government, they're going to call socialism, rightly or wrongly, and the word socialist has huge negative baggage in the United States. If we don't draw a bright line saying we are not socialists, we could end up running the risk of helping to reelect the worst president in U.S. history."

Hickenlooper failed to garner much attention from his appearances in the first round of Democratic debates. As of early August, his national polling average was less than 1%, according to RealClearPolitics.

Hickenlooper was one of the few Democrats to emerge victorious in the 2014 Republican swing midterm election that saw Republicans take control of the Senate and increase their House majority. He left office with a plurality of voters (49%) approving of his tenure, according to Morning Consult.

He had enough buzz during his second term as governor that Hillary Clinton’s campaign vetted him in 2016 as a potential vice presidential candidate. She picked Sen. Tim Kaine of Virginia.

Hickenlooper hardly registered with voters during his five-month run for the White House.

He was about 45 minutes into a campaign roundtable in Chicago last month when the moderator, Peace Coleman, forgot his name.

The governor told Coleman he should call him John.

Hickenlooper said he enjoyed his moment on the campaign trail even if it wasn't successful.

"I ran for president, because this country is being ripped apart by politics and partisan games, while our biggest problems go unsolved," Hickenlooper said. "Today, I'm ending my campaign for a president, but I will never stop believing America can only move forward when we work together."