Maine Gov. Janet Mills said on Thursday that she was suspending her primary campaign to challenge Sen. Susan Collins (R-ME), clearing the path for her Democratic primary rival, Graham Platner, to secure the party’s nomination.

“While I have the drive and passion, commitment and experience, and above all else — the fight — to continue on, I very simply do not have the one thing that political campaigns unfortunately require today: the financial resources,” she said in a statement.

Her sudden exit, with just over a month until the June primary, marks a stunning development in the closely watched race that Democratic leadership has regarded as one of its best pick-up opportunities this cycle as the party seeks to reclaim the majority in the upper chamber. 

Mills, a moderate two-term governor who had been favored by the Democratic establishment, struggled to gain traction in the race against Platner, a far-left political newcomer who had continued to maintain a commanding polling and fundraising lead, even as he has faced ongoing scrutiny for his extensive record of incendiary statements and personal controversies.

Since he entered the primary last year, Platner, a 41-year-old oyster farmer and former Marine, has weathered criticism over a now-covered Nazi tattoo whose imagery he claims not to have recognized until recently as well as a series of past online comments in which he praised Hamas’ tactics during a violent raid into Israel in 2014, among other posts that have been surfaced amid his campaign. 

He has otherwise drawn blowback for boosting extremists — telling a podcast host who has spread antisemitic conspiracy theories, for instance, that he was a “longtime fan” of his show.  

In a statement, Senate Minority Leader Chuck Schumer (D-NY) and Sen. Kirsten Gillibrand (D-NY), the Democratic Senatorial Campaign Committee chair, called Mills “a formidable governor who has broken barriers and never hesitates to stand up to bullies to fight for Maine,” adding that they “will work with the presumptive Democratic nominee Graham Platner to defeat” Collins, viewed as among the most vulnerable Senate Republicans up for reelection.

The statement, hardly a ringing endorsement of the now-presumptive nominee in a crucial battleground state, underscored the uncomfortable nature of their relationship with Platner, who has been a vocal critic of the Democratic establishment and its support for Israel.

Platner, casting himself as a populist, had won an early endorsement from Sen. Bernie Sanders (I-VT) that helped him rise to prominence at the beginning of his campaign, and has continued to claim backing from a handful of other national progressive leaders such as Sen. Elizabeth Warren (D-MA) and Rep. Ro Khanna (D-CA).

Nirav Shah, a Democrat running for governor of Maine, also announced he was endorsing Platner on Thursday after Mills had bowed out of the primary.  

Mills, whose comments did not mention Platner, has not indicated if she will back her now-former rival.

In a statement, Platner voiced gratitude for Mills’ “service to Maine” and said he looked “forward to working with her between now and November” to defeat Collins.  

Republicans, for their part, have seemed particularly eager to go up against Platner, whose vulnerabilities the Senate GOP campaign arm had been aggressively highlighting even before Mills ended her campaign.

“Chuck Schumer and Senate Democrats just coronated a phony who is too extreme for Maine,” Sen. Tim Scott (R-SC), the National Republican Senatorial Committee chair, said in a statement on Thursday. “Susan Collins has always put in the work for her constituents and delivered. Washington Democrats always fall short in Maine and will again, because they just nominated a dishonest radical.”

Collins, in comments to a CNN reporter on Thursday, praised Mills but would not weigh in on Platner as she prepares for what is now expected to be a bitterly contested general election.