Another prominent former Republican leader has broken his silence on Trump and the Republican Party Thursday, with former House Speaker John Boehner calling for the GOP to "awaken" following Wednesday's "invasion" of the U.S. Capitol.

"I once said the party of Lincoln and Reagan is off taking a nap. The nap has become a nightmare for our nation. The GOP must awaken. The invasion of our Capitol by a mob, incited by lies from some entrusted with power, is a disgrace to all who sacrificed to build our Republic," Boehner said in a tweet.

Rep. Adam Kinzinger, R-Ill., now one of Trump's fiercest critics on Capitol Hill, is the first Republican to publicly call for the invocation of the 25th Amendment to remove him from office.

"Sadly, yesterday it became clear that the president not only abdicated his duty to protect the American people and the people's house, he invoked and inflamed passions that gave fuel to the insurrection we saw here," Kinzinger said in a video posted to Twitter. "When pressed to move and denounce the violence he barely did so, while, of course, victimizing himself."

"All indications are that the president has become unmoored, not just from his duty, or even his health, but from reality itself. It is for this reason that I call for the vice president and members of the Cabinet to ensure that the next few weeks are safe for the American people, and that we have a sane captain of the ship," he added.

Kinzinger also spoke forcefully against the Electoral College challenge -- and his colleagues' support of it -- during the House debate Wednesday night over the ratification of Pennsylvania's vote.

-ABC News' Benjamin Siegel

White House Deputy National Security Adviser Matthew Pottinger resigned on Wednesday, according to a White House official and a person familiar with his resignation, joining a slate of White House staff to resign in the wake of Wednesday's rioting at the U.S. Capitol.

The White House’s National Security Council did not respond to questions about Pottinger, who was an assistant to the president.

-ABC News' Chief White House Correspondent Jonathan Karl and Ben Gittleson

Former Attorney General Bill Barr, once one of President Trump's most loyal allies, is speaking out against his former boss in light of Wednesday's storming of the U.S. Capitol, saying in a statement that his conduct "was a betrayal of his office and supporters."

“Orchestrating a mob to pressure Congress is inexcusable. The President’s conduct yesterday was a betrayal of his office and supporters," he said in a statement to the Associated Press, which was obtained by ABC News.

Barr resigned last month with five weeks remaining in Trump's term after months of growing tensions with Trump that culminated in Barr's refusal to announce investigations into Trump's political opponents and his public rebuke of Trump's baseless claims of widespread voter fraud in the 2020 election.

-ABC News' Alexander Mallin

Trump has been quiet Saturday after Twitter announced Friday evening that it had permanently suspended the president's account.

"After close review of recent Tweets from the @realDonaldTrump account and the context around them -- specifically how they are being received and interpreted on and off Twitter -- we have permanently suspended the account due to the risk of further incitement of violence," Twitter wrote in a statement.

Trump's final tweet said he would not be attending Biden's inauguration.

After Twitter's announcement, Politico reported that the president went "ballistic" and “[scrambled] to figure out what his options [were].”

Hours after his suspension, Trump released a statement criticizing the ban and teasing a possible new platform.

"I predicted this would happen," he wrote in part. "We have been negotiating with various other sites, and will have a big announcement soon, while we also look at the possibilities of building out our own platform in the near future. We will not be SILENCED!"

"Twitter is not about FREE SPEECH. They are all about promoting a Radical Left platform where some of the most vicious people in the world are allowed to speak freely," he added.

Trump had attempted to post the same statement on Twitter using the official @POTUS account, but the platform deleted the thread, saying users who are banned cannot post from other accounts.

Secretary of State Mike Pompeo blasted Twitter Saturday, comparing the ban of the president to something that would happen in China.

"Silencing speech is dangerous. It’s un-American. Sadly, this isn’t a new tactic of the Left. They’ve worked to silence opposing voices for years. We cannot let them silence 75M Americans. This isn’t the [Chinese Communist Party,]" he wrote on Twitter.

Former Ambassador to the United Nations Nikki Haley also took to the platform to draw a comparison to China writing, "Silencing people, not to mention the President of the US, is what happens in China not our country. #Unbelievable"

The White House announced Thursday that the president planned to spend the weekend at Camp David before notifying reporters that the trip was canceled. The president has nothing on his schedule Saturday.

-ABC News' Mark Osborne and Conor Finnegan