A new chapter in American history is about to unfold on the House floor. Democrats are driving President Donald Trump to the brink of impeachment as they bring abuse and obstruction charges against him to a vote of the full House.

That could happen early Wednesday evening after debate and procedural action, making the 45th president only the third commander in chief to be impeached.

But first, watch for a daylong showdown that’s been boiling for years between Republicans loyal to Trump and Democrats who say his conduct toward Ukraine makes him unfit for office.

Trump, meanwhile, is set to hold a rally in Michigan.