Dark horse Democratic primary candidate Graham Platner—an oyster farmer running on a progressive platform endorsed by Vermont Sen. Bernie Sanders—has spent the past year building momentum with the support of people across Maine and the nation.

U.S. Rep. Jake Auchincloss, D-MA, is not one of them.

Auchincloss has been calling on Platner to drop out of the Maine Senate primary since last fall, after it was revealed that Platner had a Totenkopf tattoo—an image of a skull and bones drawn in the fashion of a Nazi Germany symbol for war—on his chest.

“I find the tattoo and his commentary about it to be personally disqualifying,” Auchincloss said in a CNN interview this week. “I hope Maine voters agree with me.”

“I think that it would be a mistake for the Democratic Party to think that Graham Plattner’s brand of the Democratic Party is what wins us durable majorities throughout this country,” Auchincloss continued.

Platner, a Marine who says he got the tattoo while drunk one night in Kosovo in 2007, has had the tattoo covered up with another tattoo and has insisted that, when he got the tattoo, he didn’t know its Nazi connection.

Maine Gov. Janet Mills was running for the chance to take on Sen. Susan Collins herself, but Platner’s unexpected meteoric rise among the left flank of the party’s voters led Mills to suspend her campaign earlier this month.

To be clear, Auchincloss was directly asked about Platner this week, and that’s when he made his comments.

But Platner’s position to win the primary has Democrats divided, in Maine and throughout the country, as the Maine seat is seen as a crucial grab if the party hopes to win a majority of seats in the Senate.

And U.S. Rep. Seth Moulton, who is running a primary challenge against U.S. Sen. Ed Markey, has come to Platner’s defense.

“Look, Graham clearly made a mistake and I’ve been on CNN saying that what I appreciated about him is he owned that mistake,” Moulton said during a separate interview on CNN later that day. “He took responsibility for it and I don’t think that that’s disqualifying.” 

The Maine Senate Democratic primary now comes down to Platner vs. David Costello, an environmental policy consultant from Bangor.