With the Illinois primary just a few days away, the Democratic presidential candidates have descended upon Chicago and its suburbs, with local Democrats rallying their hometown crowds. But there is one conspicuous absence: Chicago mayor Rahm Emanuel.

The former White House chief of staff for Barack Obama is so unpopular among his constituents that he has become a political pariah on the presidential campaign trail. That’s particularly true for black voters in Chicago, who backed him in mayoral elections but are upset at the way he has handled police misconduct after several high-profile fatal shootings.

It’s no surprise Emanuel hasn’t been invited to any Bernie Sanders events, as the candidate himself said he does not want the mayor’s support. But Emanuel is a longtime confidant and friend to the Clintons, and he was nowhere to be seen at a get-out-the-vote event headlining Bill Clinton on Tuesday (March 8) in Evanston and a Hillary Clinton rally in Vernon Hills on Thursday (March 10).

“Rahm’s toxic among black voters,” wrote John Kass at the Chicago Tribune, and he “may have a contagious political illness that could threaten Hillary Clinton.”

Emanuel was excoriated for the city’s handling of a brutal shooting of Laquan McDonald by a Chicago police officer in 2014. The video of the shooting sparked national outrage, and critics claim the mayor and his aides covered up the footage for months. In December, a police officer fatally shot a mentally disturbed man and accidentally killed a bystander.

Clinton has voiced support for Emanuel as late as December 2015, but she had more cautious words just a month later on NBC’s “Meet the Press,” when asked about the mayor and the Chicago police department.

“Mayor Emanuel has said that he is committed to complete and total reform and I think he should be held to that standard,” she said. Proving his credibility is “going to be up to him and up to the people of Chicago.”

The Sanders campaign is aiming to capitalize on Clinton’s ties with the unpopular mayor with the release of a new political ad condemning Emanuel:

“In Chicago, we have endured a corrupt political system. And the chief politician standing in the way of us getting good schools is our mayor,” says Chicago school principal Troy LaRaviere. “If you have a presidential candidate that supports someone like our mayor, you have a candidate who is not willing to take on the establishment.”