Trump's allies have been the most damaging impeachment witnesses against him

But there have been weeks of this:

Rudy Giuliani, at the center of the Ukraine interference, butt-dialed an NBC reporter, and was “heard discussing need for cash and trashing Bidens.” Reporters took to Twitter and recounted their own Rudy butt-dials.

Giuliani associate Lev Parnas’ reported blabbing about his encounters with Trump may help Democrats build their case: Accounts by the WashPost and CNN have Parnas telling others he was on a “secret mission” for Trump.

And, of course, the backdrop:

The most damaging document so far was the “do us a favor” transcript of the Trump-Ukraine call that was released by the White House.

Trump stood on the White House lawn and said: “China should start an investigation into the Bidens.”