Representative Keith Ellison (D-Minn.) with colleagues at a Dec. 9, 2015, ceremony in Washington marking the 150th anniversary of the passage of the 13th Amendment. (Linda Davidson/The Washington Post)

Rep. Keith Ellison (D-Minn.) appears to be the early favorite to become the next chairman of the Democratic National Committee. He's already earned high-profile support from Sen. Bernie Sanders (I-Vt.), outgoing Senate Minority Leader Harry M. Reid (D-Nev.), incoming Senate Minority Leader Charles E. Schumer (D-Nev.) and liberals across the country.

And as we wrote last week, Ellison provides perhaps an unrivaled contrast to President-elect Donald Trump — particularly as a black Muslim from the Midwest, a region that lost the election for their party last week.

But Ellison hasn't been a stranger to controversy, either.

Earlier in his career, Ellison apologized for and/or backed off a number of controversial statements and politically dicey moves, from likening George W. Bush's consolidation of power post-9/11 to the rise of Adolf Hitler, to defending the leader of the National of Islam, to labeling his 2012 reelection opponent a “lowlife scumbag.” These comments have rarely been an issue for Ellison in his safe Minneapolis-based district, but now that he's competing to lead the Democratic Party, they've resurfaced.

Since his candidacy for DNC chair became official on Monday, conservative outlets have been quick to seize on the Hitler comments — often stretching them further than the words dictate. An Ellison spokesman is dismissing them as old attacks and emphasizes the congressman long ago denounced anti-Semitism within the ranks of the Nation of Islam. He also pointed to the congressman's work with Jewish groups and support from the Jewish community.

Here's what Ellison said back in 2007 during a meeting with a group of atheists: “It's almost like the Reichstag fire, kind of reminds me of that. After the Reichstag was burned, they blamed the Communists for it and it put the leader of that country in a position where he could basically have authority to do whatever he wanted.”

Ellison didn't say the name “Hitler,” but the arson attack on the Reichstag building — the home of Germany's parliament — in Berlin in 1933 is remembered as contributing to Hitler's consolidation of power. Hitler used emergency constitutional levers to crack down on the press and opposition groups, eventually extending the crackdown to even more civil rights.

The then-freshman congressman's comparison drew criticism from the Anti-Defamation League, which combats anti-Semitism. Then-head Abe Foxman called it “odious” and said it “demeans the victims of 9/11 and the brave American men and women engaged in the war on terror. Furthermore, it demonstrates a profound lack of understanding about the horrors that Hitler and his Nazi regime perpetrated.”

Ellison admitted it was a poor choice of words. “They told me they understood the point I was trying to make, but they didn't think it was the right way to use that historical example, because they thought any sort of comparison to the modern world we live in in some way diminishes the horror of the Nazi era. I told them I feel they're right.” At the same time, Ellison didn't back off the underlying claim that 9/11 had allowed Bush to attain too much power.

The country's first Muslim congressman has also backed off his involvement with the Million Man March in 1995 and his comments in defense of Nation of Islam Leader Louis Farrakhan. As the AP's Patrick Condon wrote in 2006, when Ellison first campaigned for Congress:

Around 1990, Ellison — then a University of Minnesota law student known as Keith E. Hakim — wrote several columns in the student newspaper that are getting a second look.

One column defended Farrakhan against charges of anti-Semitism; a second suggested the creation of a state for black residents. In 1995, Ellison helped organize a delegation to Farrakhan's Million Man March in Washington.

Ellison, 42, said he was never an enrolled member of the Nation of Islam. He got involved to help improve the lives of black men, he said, and did not fully grasp concerns about Farrakhan's anti-Semitism until after the 1995 march.

“There are legitimate concerns in the Jewish community. That's why I'm happy to answer them,” Ellison said. But, he added, “I do also think there are people out there who are fearmongering, who are trying to scare the Jewish community and manipulate this issue.”

In 2006, he said, “I wrongly dismissed concerns that [Farrakhan's comments] were anti-Semitic. They were and are anti-Semitic, and I should have come to that conclusion earlier than I did.”

He added at the time: "I have long since distanced myself from and rejected the Nation of Islam due to its propagation of bigoted and anti-Semitic ideas and statements, as well as other issues. I have a deep and personal aversion to anti-Semitism regardless of its source, and I reject and condemn the anti-Semitic statements and actions of the Nation of Islam, Louis Farrakhan, and Khalid Muhammed."

Separately, in 2001 while working as a lawyer, Ellison stood up for accused Sara Jane Olson, a member of the so-called Symbionese Liberation Army, which has been called a domestic terrorist group. Olson, formerly known as Kathleen Soliah, pleaded guilty shortly after 9/11 to attempting to murder Los Angeles police officers more than two decades prior but maintained her innocence. “I think it's dangerous to prosecute people for their political views and their political associations,” Ellison said at the time. “I think you prosecute people for what they do, for their acts.”

During his time in Congress, Ellison has sought to make inroads with Jewish groups and has spoken out against anti-Semitism.

Jeremy Ben-Ami, the president of the liberal Jewish group J Street, told The Washington Post in an interview Tuesday that Ellison is a “friend of Israel” and a “friend of Jewish people.”

“These kinds of attacks that have been leveled against him are symptomatic of a mood and fervor on the political right that needs to be countered,” Ben-Ami said, adding that Ellison is to be commended for recognizing when he said the wrong thing.

Ellison spokesman Brett Morrow added: “These are old stories the right wing has rolled out to attack Keith for years. He’s focused on moving the Democratic Party forward so all Americans can be successful — no matter their race, religion or ethnicity.”

Should Democrats pick Ellison as their party leader, they'll be picking someone with a completely unique background who would provide a huge contrast to Trump. They'll also be picking someone who, like Trump, could well be a lightning rod.