"It's not ok for someone to break the law and be above the law". The crowd started to dissipate about 6:40 p.m., but a few dozen demonstrators stayed for another half-hour.
An ever-more exasperated Trump ordered him to give up the mic and Acosta refused, with Trump branding him an "enemy of the people" and a "rude, awful person".
Those concerns are now focused on the future of the Mueller probe, which began as a look into alleged links with Russians seeking to disrupt the election and expanded into an investigation of billionaire Trump's murky finances, including his business ties to Russia.
Crowds also turned out in Chicago; Greensboro, N.C.; Chattanooga, Tenn., and many other places.
Demonstrations are taking place in more than 1,000 US cities and towns on Thursday evening-beginning at 5:00 PM (local time)-in response to President Donald Trump "installing a hack" to oversee the ongoing investigation of Special Counsel Robert Mueller.
More alarmingly for Democrats, Mr Whitaker himself had outlined a specific way to stymie the Russian Federation probe.
Sessions recused himself from managing the investigation because of his own past involvement in the Trump campaign. Justice Department officials said that under normal circumstances, the deputy attorney general would likely play an active, hands-on role in overseeing such a high-profile probe.
In the president's orbit, there remains some concern about his eldest son, Donald Trump Jr., though there are no outward indications that charges are imminent, according to a Republican close to the White House not authorized to speak publicly about private conversations. "We prosecuted the largest number of violent offenders and firearm defendants in our country's history", he said in his resignation letter.
Donald Trump has installed a crony to oversee the special counsel's Trump-Russia investigation, crossing a red line set to protect the investigation.
Trump had enjoyed Whitaker's cable TV appearances - including one on CNN in which he suggested that the Mueller probe be starved of resources - and the two men soon struck a bond.
Follayattar said the Portland protest exceeded her expectations. "If you have somebody that you trust that is saying you need to meet with this individual because they have information about her, you would take that meeting".
He said he knows little about Whitaker, other than his portrayal as a staunch "Trump loyalist". They were aimed at protesting the ouster of Sessions, whose recusal allowed Mueller to operate unimpeded, and as a warning that Whitaker should not interfere with the investigation. He also added that the fact Comey did not prosecute Trump's chief political opponent was sufficient grounds for Trump to fire him.
The Augusta protest brought out newly elected Kennebec County District Attorney Megan Maloney, who accused Trump of "sidestepping the law" in an apparent attempt to halt the investigation.
Trump forced the resignation of Sessions on Wednesday, a day after elections in which his fellow Republicans lost control of the House but increased their majority in the U.S. Senate.