A battle this weekend for control of the Democratic National Committee is poised to pull the party further to the left – the question is how far.

After a bruising series of elections during which Democrats lost the House, the Senate and finally the White House, the DNC on Saturday will choose its new chairman. The vote could mark a turning point as the party seeks to rebuild and potentially rebrand. But based on the leading candidates for the post, some see the party moving further from the mainstream.

The two top contenders, Rep. Keith Ellison of Minnesota and former Labor Secretary Tom Perez, have both garnered high-profile endorsements. Ellison has picked up support from Sen. Bernie Sanders, Sen. Chuck Schumer and Rep. John Lewis, while former Attorney General Eric Holder and former Vice President Biden have backed Perez, who served in the Obama administration. Former President Obama also has sung the praises of Perez, without formally endorsing him.

Both candidates highlight their progressive records, careers spent advocating for civil rights and grassroots work. In the 2016 presidential primaries, Perez supported Hillary Clinton, while Ellison endorsed Sanders. The election of either contender, and especially Ellison, would signal a strong shift to the left.

As the first Muslim elected to Congress in 2006, Ellison used Thomas Jefferson’s copy of the Quran for his swearing in. Though this stirred up controversy, his career spans far more provocative acts. In 1989, he defended Louis Farrakhan, the controversial leader of the National of Islam, in the University of Minnesota school paper. Fox News spoke with a fellow student who recalls confronting Ellison over his anti-Semitic remarks during his time on campus, saying that Ellison refused to engage in conversation over his remarks.

Accusations of anti-Semitism followed Ellison based on his association with Farrakhan. He asserts that he was never an official member of the Nation of Islam, but admits that he did spend 18 months organizing the Minnesota division of Farrakhan’s Million Man March in 1995.

It wasn’t until he ran for Congress in 2006 that Ellison wrote a letter to the Jewish community, apologizing for his involvement with others who held anti-Semitic views. Nevertheless, the allegations haven’t disappeared and he has been criticized for his connection to both the Council on American-Islamic Relations (CAIR) and Muslim American Society, a U.S.-based organization with suspected ties to the Muslim Brotherhood.

The Anti-Defamation League has called for Ellison to be disqualified based on “deeply disturbing” remarks he made about Israel in 2010.

In 2016, Ellison defended himself, claiming that in fighting for the African-American community, he shouldn’t have neglected the hatred and division of certain people he was associated with, but asserted that he had long since disavowed them.

Ellison has been credited with being one of the few Democrats, or Republicans for that matter, who predicted Donald Trump could win the presidency. In July 2015, On “This Week” on ABC, Ellison predicted that Trump had enough “momentum” to actually win. The rest of the panelists erupted into laughter. He was unquestionably opposed to Trump’s presidency, but Ellison was paying attention to the early signs that Trump could, and ultimately did, win. On Wednesday, Trump tweeted, “One thing I will say about Rep. Keith Ellison, in his fight to lead the DNC, is that he was the one who predicted early that I would win!”

Perez graduated from Harvard Law School in 1987 and later worked as a civil rights attorney at the U.S. Department of Justice. He went on to serve as deputy assistant attorney general for civil rights under AG Janet Reno. Perez joined the Montgomery County Council in Maryland in 2002 as the first Latino to sit on the council and then became its president in 2004, serving until 2006. During the Obama administration, he returned to the Department of Justice as assistant attorney general for civil rights in 2009 and went on to serve as the Obama-appointed secretary of Labor from 2013 until 2017.

While Perez generally is seen as the more mainstream candidate, there are those who believe his politics are still fairly radical. J. Christian Adams, former attorney at the U.S. Department of Justice, has a contentious history with Perez. Adams accused the Justice Department of racial bias in dropping a New Black Panthers voter intimidation case, and further alleged that Perez lied under oath in hearings before the U.S. Commission on Civil Rights.

“Based on my firsthand experiences, I believe the dismissal of the Black Panther case was motivated by a lawless hostility toward equal enforcement of the law,” he wrote.

When asked about Perez’s capability to serve as the DNC chair, Adams told Fox News, "He testified falsely under oath about the New Black Panthers dismissal and told the DOJ inspector general he didn't think cases should be brought to protect white voters. He'll make a perfect chair for the modern Democratic Party."