WASHINGTON — Buckle up.

Beltway Democrats are quietly bracing for more politically damaging details to emerge on embattled Maine Senate hopeful Graham Platner and fretting that he could jeopardize their already narrow path to retaking the Senate this cycle.

“It’s not a possibility that more will come out. It’s a certainty. Someone who behaves like this almost never behaves like this in isolation. I’m sure there’s a pattern of this kind of behavior he’s had throughout his life,” a Democratic staffer on Capitol Hill told The Post.

“I’m sure more will come out in terms of his relationships with women, and he’s an embarrassment to the party.”

Platner’s scandal has put Democrats in an uneasy position. The horny oyster farmer is beloved by elements of the base, whom lawmakers don’t want to alienate. Yet he is also increasingly becoming a liability and giving Republicans fodder.

Prominent pols such as Sens. Cory Booker (D-NJ), Andy Kim (D-NJ) and Chris Murphy (D-Conn.) have either distanced themselves from Platner or, as much as possible, sidestepped the candidate’s recent sexting scandal.

Meanwhile, lefty Dems such as Rep. Ro Khanna (D-Calif.) and Sen. Bernie Sanders (I-Vt.) have remained supportive despite fears of other skeletons in Platner’s closet.

Senate Minority Leader Chuck Schumer is standing by Platner, even after a deluge of recent reports on the candidate’s racy text messages with other women while he was married.

“I met with Graham Platner today. We’re going to beat Susan Collins and take back the Senate,” Schumer told reporters several times during a tense Tuesday news conference when asked about the candidate’s appearance in Washington, DC.

Wild rumors about Platner have swirled for months. Some Democratic operatives are fearing that Republicans may be sitting on something devastating or that a bombshell could emerge just before the general election.

“At this point, speculation about Graham Platner’s next problem isn’t speculation anymore,” one Democratic operative told The Post. “It’s just waiting for confirmation.”

“It’s time to stop asking whether there is worse news to be uncovered about Graham Platner, and instead ask what time do we think it will post.”

On social media, several prominent X accounts have hinted at some of the rumors circulating.

“[T]here are whispers about potential trouble ahead on a related front that could cause problems,” conservative commentator Guy Benson wrote after the sexting scandal emerged.

Already, Platner has survived revelations about a tattoo on his chest with Nazi links that he denies knowing about and a bevy of social media posts in which he trashed a famous Purple Heart veteran, downplayed sexual assault, riffed about hookers, defended soldiers urinating on dead Taliban fighters, called war “the most enjoyable experience,” declared that white Americans “actually are” racist and stupid, and more.

Given that history, Platner had been adamant in multiple interviews that there were no more skeletons in his closet.

“No,” he emphatically told CNN’s Manu Raju in January. “My life is not very complicated. And no, there’s not anything else coming.”

A slew of revelations about his Reddit past emerged since that interview. Then, last month, he similarly suggested to the New York Times that nothing else was coming.

But on Saturday, bombshell reports emerged that he allegedly sexted multiple women while married to his wife, with whom he tied the knot in 2023.

“Where there’s smoke, there’s usually fire. At this point, we’ve seen enough embers to know there’s something there, but we haven’t found the fire yet,” one Republican operative told The Post.

The primary is on June 9, though there are avenues for Democrats to replace him after the fact if Platner decides to quit.

“If we keep Platner as a candidate and he wins or even if he doesn’t win, we’ve lost the moral high ground,” the congressional staffer added. “He’s a disgrace.”

The Marine veteran is the presumptive Democratic nominee because his top primary foe, Maine Gov. Janet Mills, suspended her campaign in April, though she stressed Monday that she’s “still on the ballot.”

Platner has a 7.8 percentage-point polling edge over incumbent Sen. Susan Collins (R-Maine), according to the latest RealClearPolitics aggregate of polls. But Collins previously overperformed the RCP aggregate dramatically during her 2020 re-election bid.