Thousands of demonstrators hit downtown Chicago streets Thursday evening to protest any potential attempt by President Donald Trump to block Special Counsel Robert Mueller’s investigation into alleged Russian meddling in the 2016 election.

U.S. Sen. Dick Durbin was among the half-dozen speakers at a 5 p.m. rally in Federal Plaza who criticized the firing of Attorney General Jeff Sessions on Wednesday, the day after Democrats regained control of the House of Representatives in the midterm elections.

“If this president believes he can stop the Mueller investigation and get by with it, then I believe we have reached a point in our democracy which is very sad and very troubling,” Durbin said. “We need to hold this president accountable, and we need to do everything in our power to stop any interference with this Mueller investigation.”

State Sen. Daniel Biss joined in the chorus of anger, calling Sessions’ replacement, Acting Attorney General Matthew Whitaker, unfit to oversee the special counsel’s probe.

“They’re not fooling anyone,” Biss said. “No one is above the law. Not just the president, but especially the president.”

Whitaker, who served as Sessions’ chief of staff, has previously said the Mueller investigation overstepped its bounds, and that there was “no collusion” between then-candidate Trump’s campaign and the Russian government. It is not clear what led Whitaker to those conclusions.

More than a half-hour after the rally began, the group of about 2,000 protesters marched to Trump International Hotel and Tower.

Several downtown streets were shut down as the crowd chanted, “This is what democracy looks like,” and, “No Trump, no KKK, no racist USA,” while Chicago police escorted protesters through the Loop. The crowd started to dissipate about 6:40 p.m., but a few dozen demonstrators stayed for another half-hour.

Evanston resident Prasanna Raghav works in the Loop and stepped outside his office to join the march because “everyone needs to get involved.”

“I can’t sit at home and watch what’s happening. How can you normalize this? This is not normal,” Raghav said. “If you’re going to sit at home and just keep watching MSNBC, CNN, FOX and everything on loop, nothing is going to change.”

Raghav said those upset with Trump’s actions should demonstrate in full force to show the president how they feel.

“I think [Trump] needs to be reminded that he represents the people, and that the attorney general is not just his butler-boy who he can just fire and hire,” Raghav said. “That’s not how it works.”

Roxanne Tam, a native New Yorker studying at the University of Chicago, said Trump’s latest moves are “egregious” oversteps.

“[The protest] sends a message of cohesion that we are one nation together, and we do not like the unconstitutional actions [Trump] is taking,” Tam said. “He has prioritized his own safety, his own reputation, over the safety of our nation.”

The Chicago protest joined others in cities across the nation protesting Trump’s action this week.

A coalition of progressive groups organized the nationwide event, called “Mueller Protection Rapid Response.” The demonstrations started at 5 p.m. local time in places including New York City’s Times Square and in front of the White House.

Also on Thursday, 18 attorneys general, including Illinois Attorney General Lisa Madigan, called for the recusal of Whitaker from Mueller’s investigation.

In a letter sent directly to Whitaker, the attorneys general said Whitaker’s recusal was needed to “maintain public trust in the integrity of the investigation.”