(CNN)Former Colorado Gov. John Hickenlooper plans to end his bid for the 2020 Democratic presidential nomination on Thursday, three Democrats familiar with the matter tell CNN, as he continues to weigh a bid for the Senate. Hickenlooper, who struggled to break out of the crowded Democratic field, has not yet decided whether he will run for the Senate as party leaders have urged him to do, sources said. He does not plan to make an announcement on that decision Thursday. Hickenlooper's failed bid looked to stem 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 in the primary race and Hickenlooper's campaign lost three of their most senior staffers in early July, including Brad Komar, the governor's 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. Hickenloopers 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. Even in that 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.

See  more