Susan Collins

But in Washington, signs of how divisive the Maine general election will become quickly emerged. Both parties began to lay out their lines of attack in a contest that both sides have described as central to their midterm strategies.

President Donald Trump used an appearance in the Oval Office to deliver a two-minute monologue attacking Platner, calling him a “thug” nearly a dozen times and assailing Democratic leaders for supporting his bid.

“He’s worse than any human being that’s ever run for office, probably,” Trump said. “He’s a cheap, no-good person.”

The president offered tepid praise for Sen. Susan Collins, the moderate Republican whom Platner is trying to unseat, saying that while “she’s not my best friend at all,” she was “a sane person.”

Facing a difficult national political environment, Republicans are hoping to transform the contest into a referendum on Platner’s character and his liberal positions on issues like universal childcare, “Medicare for all” and immigration enforcement.

They are warning donors that Platner remains a strong contender for the seat, even after a series of scandals over his past conduct and statements that have made some Democrats nervous about his candidacy.

“The political fundamentals in Maine remain challenging, and it is a fatal mistake to assume Platner is too damaged to win,” the Republican Senate campaign arm wrote in a memo released Wednesday morning. “National donors and supporters should not mistake Democrat discomfort for Democrat retreat.”

In the hours after Platner’s primary victory, Democratic leaders in Washington appeared to grudgingly accept his candidacy, offering restrained support for his bid.

Sen. Chuck Schumer, D-N.Y., the minority leader, and Sen. Kirsten Gillibrand, D-N.Y., the chair of the Democratic Senate campaign arm, released a joint statement of support that predicted that Platner would defeat Collins, though it included no words of praise for the party’s nominee or his primary campaign. The Senate leaders’ preferred candidate, Gov. Janet Mills of Maine, suspended her bid in April after struggling to match Platner’s fundraising and voter enthusiasm.

Their statement, which focused on Collins, offered a preview of their general election strategy of making the contest about the incumbent’s five terms in the Senate and her support for the Trump administration.

“Platner’s agenda supports working people and families, while Collins upholds Washington’s status quo,” Lauren French, a spokesperson for the main super political action committee supporting Democratic Senate candidates, said in a statement.

Platner echoed that message in his early attacks, casting Collins as an “establishment politician who doesn’t really believe in anything” in an interview Wednesday morning on MS NOW’s “Morning Joe.”

His first campaign ad of the general election focused on the ties between Jeffrey Epstein, a convicted sex offender, and both Republicans and Democrats.

“The only thing the party establishments can agree on is a love of Jeffrey Epstein and a hatred of me,” Platner said in the spot.

He has also highlighted Collins’ support for the 2018 Supreme Court confirmation of Justice Brett Kavanaugh, who later voted to overturn federal abortion rights. Asked by a CNN reporter Wednesday whether she regretted her vote, Collins declined to respond.

“The people of Maine know me well, and I know them well,” she said in response to a previous question about Platner’s attacks.

Among Democrats, divisions -- and concerns about Platner’s past -- linger.

Throughout his primary campaign, Platner has been trailed by controversies, including a tattoo he had that resembled a Nazi symbol, a history of inflammatory online posts and reporting from The New York Times in which women he dated accused him of engaging in unsettling behavior.

Platner has pointed to his struggles with post-traumatic stress disorder after his combat tours with the Marines. He has also denied allegations that he was physically intimidating to women. He has sought to raise doubts about the claims by noting that one woman who spoke with the Times has worked in conservative politics.

Sen. Mark Warner, D-Va., urged Platner to take more aggressive steps to dispel the allegations.

“I do wish this, that if Mr. Platner feels that he could -- and I’ve never met him -- if he could disprove some of these accusations, I think that would be important,” he said in an interview Wednesday on CNN.

In the nearly 30-minute interview on “Morning Joe,” Platner was repeatedly pressed about revelations regarding his past and concerns that explicit photos or text messages could be weaponized against him.

He said that such issues were largely irrelevant to voters in Maine.

“I just want to make this clear: There’s nothing out there that’s actually concerning,” he said. “People will make everything seem very concerning, because that’s what people do in politics.”

Recent revelations of explicit text messages he sent to women while he was married were being “blown out of proportion” by news outlets and his opponents, he said.

“Since this thing started, we have been told time and time again by supposed political geniuses who are professionals and really know what they’re doing, that the campaign was over,” said Platner, clad in a purple hooded sweatshirt.

He added: “We’ve been counted out time and time again. And then it doesn’t happen.”