Montana Governor Steve Bullock is ending his presidential campaign, citing an inability to gain traction with Democratic primary voters.

“While there were many obstacles we could not have anticipated when entering this race, it has become clear that in this moment, I won’t be able to break through to the top tier of this still-crowded field,” Bullock, 53, said in a statement Monday.

The two-term governor was part of a group of moderate candidates, including John Hickenlooper, John Delaney and Tim Ryan, who criticized liberals such as Bernie Sanders and Elizabeth Warren for pushing the party too far to the left.

He stressed his record of bipartisanship and pragmatism as a Democrat in a Republican-leaning state, saying he won re-election in 2016 by 4 percentage points, even though President Donald Trump carried Montana by 20 points.

His signature issue was curbing the influence of so-called dark money in politics, which he said he’d done successfully in Montana and vowed to do nationally.

Bullock waited to join the race until May when the Montana legislative session was over, making him one of the latest entrants and putting him at a disadvantage compared with better-known candidates. He failed to clear the bar to participate in the first debate of Democratic candidates.

He participated in the second debate in Detroit in July and made his mark by assailing criticizing Sanders’s Medicare for All proposal. He also clashed with Warren after she called for decriminalizing illegal border crossings.

“You are playing into Donald Trump’s hands,” he said.

He failed to meet the criteria for September and October debates, and has languished in the polls and failed to catch fire in fund raising.

He stood out as a Democrat who has been able to pass a relatively progressive agenda in a Republican-held legislature and as the only Democrat in the field who won in a state Trump carried in 2016 by 20 points.

Bullock graduated from Claremont McKenna College and has a law degree from Columbia Law School. Before being elected governor in 2012, Bullock was a lawyer in private practice up until being elected Montana’s attorney general in 2008.

“On the difficult days, I would joke, ‘It’s worth the sacrifice because it’s only a fair shot at the American Dream and our representative democracy at stake,’” Bullock said in the statement Monday. “That truth remains. Yet, even throughout the challenges of the campaign, I have experienced the best of what America offers.”