"It's not ok for someone to break the law and be above the law".
The organizers of Thursday's events warned of even more massive street protests if Trump fired Deputy Attorney General Rod Rosenstein, who had been overseeing the Mueller investigation after Sessions recused himself.
Several people were invited to speak during the protest, which lasted about 40 minutes. "I had no clue there would be this many people", Follayattar said.
One reason Sessions endured months of taunting from Trump is that he believed he was protecting the integrity of the Justice Department and was trying to prevent the president from bringing in someone who would politicize it, according to a US official who has worked with Sessions and frequently talked with him.
Overseeing it all is Whitaker, a former college football player and United States attorney from Iowa who was brought into the Justice Department past year to serve as Sessions' chief of staff.
"He'll have no qualms whatsoever about attempting to undermine Mueller's investigation", said Fein.
Trump saw the move as a betrayal and frequently and publicly criticised Sessions for making the decision to recuse himself. In fact, it allows Mueller to pursue "any matters that arose or may arise directly from the investigation".
Whitaker promised that the organization he led at the time, the Foundation for Accountability and Civic Trust, would "continue to press its investigation into these 17 attorneys general for more information and answers regarding the true motivation and the real agenda behind this reprehensible campaign". Those prosecutors have secured Cohen's cooperation in ongoing investigations, as well as that of Allen Weisselberg, a longtime accountant for the Trump family's real estate empire.
In the House of Representatives, the senior Democrat on the Intelligence Committee - which Democrats will control from January - sounded the alarm.
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. Commenting on Trump's pick, Christie said he wanted to finish his term as New Jersey governor.
Whitaker is a former USA attorney from Iowa who founded a law firm with other Republican Party activists.
Before going to the Trump administration, Whitaker had a cushy job at a conservative nonprofit funded by dark money.
"We are facing a continuing assault on our democracy", she said.
"You would always take that meeting".
Whitaker's argument that Mueller doesn't have authority to investigate Trump's opaque personal finances is ridiculous.
While Whitaker is now Mueller's supervisor, it was not clear Thursday whether that meant Rosenstein would step aside.
"And to outsiders, it looks like he [Trump] chose this person because this person has committed to end this investigation, this person is loyal to Donald Trump". Protestors anxious Whitaker would use his new position to stifle the investigation before its conclusion.
A large crowd marched to downtown Seattle on Thursday evening to call for protecting special counsel Robert Mueller's investigation into potential coordination between Russian Federation and President Donald Trump's 2016 campaign.
He can also block Mr Mueller from subpoenaing Mr Trump or bringing an indictment, although he must notify Congress if he does so.
Meanwhile, President Donald Trump's legal team has begun working with the president to craft responses to questions from Mueller's team as part of their investigation, sources close to Trump told ABC.