WASHINGTON – Sen. Al Franken plans to stay in the U.S. Senate and try to win back Minnesotans' trust.

The Minnesota Democrat, who has been accused by four women — two of them anonymously — of inappropriate contact, issued a Thanksgiving afternoon apology and pledge. He wrote that he "feels terribly that I've made some women feel badly." He called himself "a warm person" who likes to hug people when they're being photographed with him, but clearly, his embrace "crossed a line for some women."

Although his statement did not directly address the question of whether he might resign, he vowed to move ahead with an effort to regain the trust of his constituents. A spokesman for Franken said Thursday that the senator has no plans to resign.

The accusations, which have left Franken facing a Senate ethics investigation, have touched off a fierce debate among his progressive supporters over what level of sexual misconduct should force a politician with a record of support for women's rights to resign from office.

"Because he happens to be a good guy on some other issues, people are confused," said Erin Vilardi, head of VoteRunLead, a national group that aims to elect more women to public office. It held a national convention in Minneapolis last weekend.

Vilardi spoke after the first two accusations against Franken and before Wednesday's Huffington Post report of the third and fourth allegations. The website cited two unidentified women who said he grabbed their buttocks in separate incidents. Each spoke on condition of anonymity about events they said occurred during Franken's first Senate run.

The first said Franken groped her when he posed for a photo with her after a June 2007 event hosted by the Minnesota Women's Political Caucus in Minneapolis. The second told HuffPost that Franken cupped her butt with his hand at a 2008 Democratic fundraiser in Minneapolis, then suggested the two visit the bathroom together.

The accusations against Franken have emerged in a charged atmosphere of accusations and denials in a broad swath of American life — politics, the arts, media and business. In Minnesota, accusations by several women against state Sen. Dan Schoen, a DFLer, and state Rep. Tony Cornish, a Republican, led both to say they'll resign.

The first accusation against Franken came last week, when Los Angeles radio broadcaster Leeann Tweeden tweeted that he forcibly kissed and groped her during a 2006 USO tour. He apologized to her but added that he remembered their encounter differently.

On that same tour, the former "Saturday Night Live" cast member also mugged for a photo with his hands hovering over Tweeden's breasts as she slept.

On Monday, a second woman accused Franken of unwanted sexual touching. Lindsay Menz, 33, contacted CNN to say that Franken grabbed her buttocks while they posed together for a photo at the Minnesota State Fair in 2010. Menz now lives in Texas.

Franken told CNN that he did not remember posing for the photo with Menz.

"I take thousands of photos at the State Fair surrounded by hundreds of people, and I certainly don't remember taking this picture. I feel badly that Ms. Menz came away from our interaction feeling disrespected," Franken said in a statement to CNN.

Speaking after the Tweeden and Menz accusations, Vilardi described participants at the VoteRunLead convention as torn over what to think about Franken. Just because women know a man in one light, she said, that "doesn't make it impossible that they've treated other women like crap."

Many Democrats and progressives have argued that other politicians, including President Donald Trump and Alabama U.S. Senate candidate Roy Moore, have been accused of worse misconduct. More than 50 women who worked with Franken have spoken out in support of him, saying he treated them with respect at workplaces ranging from the Senate to the "SNL" soundstage.

But Minnesota Republicans have jumped on the allegations. Jennifer DeJournett, a GOP activist, started a petition demanding his resignation after the first allegation. Signatures spiked further after the other accusations.

If Franken were to step down, Gov. Mark Dayton would appoint a temporary replacement, and a special election would be held next November for his seat.

'I crossed a line ...'

In Thursday evening's statement, the senator wrote:

"I've met tens of thousands of people and taken thousands of photographs, often in crowded and chaotic situations. I'm a warm person; I hug people. I've learned from recent stories that in some of those encounters, I crossed a line for some women — and I know that any number is too many.

"Some women have found my greetings or embraces for a hug or photo inappropriate, and I respect their feelings about that. I've thought a lot in recent days about how that could happen, and recognize that I need to be much more careful and sensitive in these situations. I feel terribly that I've made some women feel badly and for that I am so sorry, and I want to make sure that never happens again.

"And let me say again to Minnesotans that I'm sorry for putting them through this and I'm committed to regaining their trust."

A spokesman said Franken will speak with the media on Sunday.

Staff writer Maya Rao contributed to this report.