Barely 11 months after U.S. President Donald Trump was acquitted in a momentous Senate trial, the nation now confronts the possibility of yet another impeachment battle in the twilight of his presidency, a final showdown that will test the boundaries of politics, accountability and the Constitution.

No president has ever been impeached for high crimes and misdemeanors twice. But House Speaker Nancy Pelosi was weighing bringing a new article of impeachment to the House floor as early as Monday charging Trump with "incitement of insurrection” for encouraging the mob that ransacked the Capitol to disrupt the solemn process finishing his own election defeat.

If Pelosi proceeds, the House could approve the article in days, this time with the support of even some disaffected Republicans, sending it to the Senate for a new trial unlike any of the previous three in American history.