Updated

Minnesota Rep. Keith Ellison remains the frontrunner to take over the beleaguered Democratic National Committee but is facing growing questions not only about his controversial past but whether he can effectively lead the group without relinquishing his House seat.

The call for a full-time DNC leader -- and for Ellison to step down from the House if he gets the job -- is being led by former committee Chairman Howard Dean, who last week ended his bid to return to the post.

Dean made the announcement before a gathering in Denver of Democratic state party leaders, after which Ellison purportedly said with mixed emotions that he is considering leaving Congress to devote his full attention to the DNC.

Dean made clear he considers Ellison's exit from Congress a requirement. He afterward told MSNBC, “I do not support Keith as long as he has his congressional seat. I do not believe you can do this job and another job in Congress. I don't support Keith. Maybe I will later.”

The other remaining DNC candidates are Ray Buckley and Jamie Harrison, the chairmen, respectively, of the New Hampshire and South Carolina state Democratic parties.

Beyond concerns about splitting duties, Ellison, the first Muslim elected to Congress, is facing criticism about his past remarks on Israel and association with Nation of Islam leader Louis Farrakhan.

“Keith Ellison is, by all accounts, a decent guy,” Alan Dershowitz, a renowned Jewish lawyer and legal scholar who supports Democratic candidates, said in a FoxNews.com op-ed. “But it is hard to imagine a worse candidate … Ellison represents the extreme left wing of the Democratic Party, just when the party -- if it is to win again -- must move to the center in order to bring back the voters it lost to (Donald) Trump.”

Ellison, in his sixth term, would take over the committee after a bruising 2016 election cycle in which Democratic presidential nominee Hillary Clinton was upset by Trump, the Republican nominee, after essentially leading the entire race.

In addition, Washington Democrats missed their best opportunity in years to retake control of the Senate, gaining just two seats while winning only a handful of House seats and again losing more gubernatorial and state legislative seats across the country. (Democrats could pick up a third Senate seat in Saturday’s runoff election in Louisiana.)

Clinton’s White House bid was set back on the eve of this summer’s Democratic National Convention when leaked emails revealed DNC Chairwoman Debbie Wasserman Schultz and some of her staff appeared to favor Clinton over primary rival Sen. Bernie Sanders -- who appealed to the electorate’s far-left wing and who backs Ellison’s bid.

Schultz resigned, but the DNC’s problems continued when more leaked emails, in the closing weeks of the White House race, revealed that interim-DNC leader and former CNN contributor Donna Brazile had given the Clinton campaign questions in advance of a network-sponsored debate and town hall forum.

Ellison reportedly argued at the meeting last week that he could handle both jobs, especially in a GOP-controlled Congress, just as Wasserman Schultz, a Florida congresswoman, did. The argument was not well received.

“I’ll leave that up to you guys to make that determination,” Harrison reportedly said to chortles.

The DNC charter also appears to automatically prohibit Ellison or anyone else from holding both posts, as it stipulates the chairman “shall serve full time.”

However, an allowance seemed to have been made when President Obama personally appointed Wasserman Schultz.

Dershowitz further suggested that beyond Ellison’s questionable ideology the DNC needs a leader who can reconnect the party with disaffected centrist voters.

“The centrist voters they lost to Trump will only be further alienated by the appointment of a left-­wing ideologue who seems to care more about global issues than jobs in Indiana, Wisconsin and Michigan … . Ellison’s sordid past associations with Louis Farrakhan … will hurt him in middle America.”

The 68-year-old Dean, a Clinton supporter, also said last week that he dropped his DNC bid because he thought the party needed a younger face and that he didn’t want to get involved in an “ideological fight” between the party’s establishment and progressive wings.