John Hickenlooper, former governor of Colorado and 2020 presidential candidate, pauses while speaking during the Progress Iowa Corn Feed in Cedar Rapids, Iowa, U.S., on Sunday, July 14, 2019.

Former Colorado Gov. John Hickenlooper dropped out of the 2020 Democratic presidential primary race on Thursday as he struggled to gain traction in a crowded field.

"I ran for president because this country is being ripped apart by politics and partisan games while our biggest problems go unsolved. Now today, I'm ending my campaign for president, but I will never stop believing that America can only move forward when we work together," Hickenlooper said in a video shared on social media. He added that he expected a "very different conclusion" from his presidential bid.

Hickenlooper tweet: This morning, I'm announcing that I'm no longer running for President. While this campaign didn't have the outcome we were hoping for, every moment has been worthwhile & I'm thankful to everyone who supported this campaign and our entire team.

Colorado Democrats have urged Hickenlooper to abandon his bid and instead join the state's U.S. Senate race, where his party hopes to unseat Republican incumbent Cory Gardner. In the video Thursday, Hickenlooper said he heard "from so many Coloradans who want me to run for United States Senate." He said he would "give that some serious thought."

Democrats have perhaps their best chance to flip a GOP-held seat next year in Colorado. Already, more than 10 Democrats have jumped into the Democratic Senate primary. As he has high name recognition from two terms as Colorado's governor, Hickenlooper would immediately become a top contender for the Senate seat if he entered the contest.

Hickenlooper, a moderate, failed to attract much attention after declaring his presidential candidacy in March. He generally sat at 1% in the polls. He raised just $1.1 million in the second quarter, among the lowest hauls of any of the candidates.

Hickenlooper's paltry second-quarter fundraising placed his campaign in danger of running out of money, according to Politico.

His campaign endured a shake-up in early July when five high-level staffers left or made plans to leave, Politico reported.

During July's Democratic primary debate Hickenlooper joined other moderates in attacking progressives, warning that Democrats' "Medicare for All" proposals would turn off voters. "This notion that you're going to take private insurance away from 180 million Americans," he said, "is a disaster at the ballot box, you might as well FedEx the election to Donald Trump."

Hickenlooper's campaign had touted his leadership and success in implementing policies that accomplished near universal health-care coverage, strong gun control measures and the legalization of recreational marijuana during his two terms as Colorado's governor.

Hickenlooper, 67, was Colorado's governor from 2011 to 2019. He was Denver's mayor for eight years before that.

The Colorado Senate race has drawn intense national interest as Republicans and Democrats fight for control of the chamber next year. The top fundraiser in the Democratic primary, former state Sen. Mike Johnston, raised $1.6 million in the second quarter — more than Hickenlooper did as a presidential candidate.

— CNBC's Kevin Breuninger contributed to this report