(CNN) Montana Gov. Steve Bullock ended his presidential campaign on Monday, the Democrat announced in a statement to CNN.

The decision comes after the moderate Democrat failed to convince the party's base that the best way to defeat President Donald Trump was by nominating someone who can win in a red state.

"Today, I am suspending my campaign to become the Democratic Party's nominee for President," Bullock said. "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 of candidates."

Bullock, who is term-limited as governor, will not take on Republican Sen. Steve Daines in 2020, his spokeswoman said.

"Governor Bullock will continue to faithfully and effectively serve the people of Montana as their Governor," said Bullock spokeswoman Galia Slayen. "While he plans to work hard to elect Democrats in the state and across the country in 2020, it will be in his capacity as a Governor and a senior voice in the Democratic Party -- not as a candidate for US Senate."

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