[x]

In 1868, President Andrew Johnson would have been convicted if even a single member of his own party had voted against him.

What was Johnson's party? I believe he had been a Democrat, but was elected VP on a National Unity ticket with Republican Abraham Lincoln. I don't think he was welcome in either party by 1868.

And why did the House impeach him in an election year? He obviously wasn't going to be reelected without a party endorsement, and probably would have been gone in a year anyway.

[LS]

The House impeached him because, like Trump, they just hated him.