Hundreds of people rallied in front of Austin City Hall on Thursday evening, joining protesters across the nation, to demand that federal lawmakers protect Special Counsel Robert Mueller’s investigation into ties between Russia and Donald Trump’s presidential campaign.

Activists rushed to organize the protests after news broke Wednesday afternoon that Trump asked for U.S. Attorney General Jeff Sessions to resign, and replaced him with Matthew Whitaker, Sessions' chief of staff. Whitaker has publicly criticized Mueller’s probe.

In Austin, the protest's organizers made it clear that they had three demands: Whitaker must recuse himself from the investigation, the investigation must continue and the new attorney general must be impartial.

At City Hall, people held signs that expressed sentiments such as "Whitaker Must Resign" and "No One Is Above the Law." One woman wore a jacket with "Save Mueller" emblazoned on the back.

Austin Council Member Jimmy Flannigan and U.S. Rep. Lloyd Doggett both spoke at the event.

"This is a rally — like those going on across America tonight — about no one being above the law. ... We all know that what Trump fears the most is truth," Doggett said. "The truth that Mueller could reveal about collusion to subvert our elections ... about money laundering and obstruction of justice."

Doggett said he was no fan of Sessions, but he "was at least willing to recuse himself properly on the recommendation of the ethics people in the Justice Department from this investigation." Doggett called Whitaker "a political hack, who has already publicly condemned the Mueller investigation and has proposed impeding it by doing things like cutting off its budget."

Giselle Roberts, who attended the rally with friends, said she was glad she came out Thursday evening.

"At this point, I consider it a bipartisan issue," Roberts said of Mueller's investigation. "It's a matter of upholding the law. We need to unite as a country."

Roberts said she felt optimistic after hearing the speakers.

"I feel a lot more hopeful in these incredibly dark times," she said.