In a statement shared with POLITICO, Golden recalled a recent discussion about the presidential race where a voter described Bennet as “calm, thoughtful, honest and humble: In other words, he doesn’t stand a chance.”

“That’s the kind of cynicism too many of us have come to expect of our politics these days,” Golden said, citing Bennet’s work to end gerrymandering and big money in politics. “These qualities should be exactly the things we look for in a leader.”

A Marine veteran and former staffer to GOP Sen. Susan Collins, Golden ousted then-GOP Rep. Bruce Poliquin in 2018 from a rural Maine district that hasn't dispatched an incumbent in over 100 years. And he will have an especially complicated reelection that could be quite susceptible to top-of-the-ticket trends. The district voted for Trump by 10 points in 2016 after backing President Barack Obama by nearly that margin four years earlier.

Maine is one of two states that divides its Electoral College votes by congressional district, meaning the president has incentive to spend in the district, which spans much of the northern and central regions of the state. It is also the only state in the country that runs federal elections under a ranked-choice voting system.

Golden did not beat Poliquin outright in 2018, but only after the votes for two third-party candidates were redistributed. It's unclear if any third-party contenders will appear on the ballot in 2020.