This is a long and sordid tale.

A timeline of Trump, Guiliani, Biden, Ukraine

I started at the top and got bored fast, so I skipped to the bottom and was all, WTF?!, so I had to go back to the middle.

This isn't your average scandal. This is withholding taxpayer approved military support to an ally nation at war for personal gain.

This is way beyond chirping nonsense and lies about "chain migration" while having personally chain migrated his in-laws.

But again... he's gotten away with so, so much so far that I can't even predict how this goes down.
The idea that he will ultimately get away with it is still near certain. He'll never be convicted of anything, and if he is, he'll be pardoned by Pence. Not that the notion that he'll get impeached can be taken seriously at this time.