In the aftermath of a shocking, destructive invasion of the U.S. Capitol by domestic terrorists who were incited to action by President Trump, Americans have some hard truths to face.

This is a president who has gone rogue. The top priority now for Vice President Mike Pence, Congress and other leaders must be how best to protect this country from a leader who is demonstrably unfit for office. They must present a unified front to restrain a president whose lack of remorse and unwillingness to take responsibility for what happened are ample evidence that his judgment cannot be trusted.

Trump issued a 4 a.m. statement Thursday, shortly after Congress affirmed the election results, saying that he would go along with the transition on Jan. 20, Inauguration Day. But there is no guarantee he will do so, and there is much damage he could do in the coming days. House Speaker Nancy Pelosi and Sen. Chuck Schumer, soon to be majority leader, have called on Pence to invoke the 25th Amendment to remove Trump from office. Failing that, both leaders support impeachment. Certainly there is justification for both, but neither is likely. Impeachment is a process designed to move slowly. The 25th Amendment can be swift, but it requires a degree of unity and purpose that may be difficult to achieve.

That said, there are a growing number of former Trump acolytes finally acknowledging openly how far off the rails this president has gone. Former White House Chief of Staff Mick Mulvaney said in a CNBC interview that Trump has become increasingly erratic.

“Clearly he is not the same as he was eight months ago, and certainly the people advising him are not the same as they were eight months ago,” Mulvaney said, “and that leads to a dangerous sort of combination as you saw yesterday.” Former U.S. Attorney General Bill Barr, who left office recently, issued a statement calling Trump’s conduct a “betrayal of his office.”

Trump’s actions have triggered a wave of resignations that now include at least one Cabinet member, Transportation Secretary Elaine Chao, wife of Senate Majority Leader Mitch McConnell.

Reportedly there are high-level discussions among top Republicans urging aides and others to stay and do what they can to maintain some semblance of order. That is the proper course. Trump in his current state should not be in the position to further erode norms by installing those even more willing to do his bidding.

Congress must also move quickly to conduct a thorough and unflinching investigation into the stunning failure of U.S. Capitol Police to secure the building and protect those inside from a raging mob. No weak protestations of being “unprepared” or “overwhelmed” will suffice here.

What should have been an impregnable fortress on a day when this country’s most important leaders were gathered to certify an election was exposed as being almost comically easy to crack. The world will not soon forget the sight of the mob scaling the walls, breaking windows and rampaging through the Capitol. Steps must be taken to ensure there is no repeat episode. Ever.

Those involved in the insurrection and their accomplices should be tracked down and prosecuted.

Finally, while Congress did finally certify the election results, 147 lawmakers, hours after the invasion, still fed into the delusion by voting against certification and fomenting further doubt about an election outcome that has been clear since November.