Good evening to you this Sunday. I'm Ari Melbert. Welcome to our special MSNBC series, Trump and Ukraine, the impeachment crisis.

Tonight, we have for you a new special report on what are clearly these extraordinary developments in the impeachment probe,

including the parade of witnesses defying the White House with damning testimony about the president's conduct.

Now, key aids admitting on live national TV to the bribery at the center of the Ukraine plot.

We have special experts joining us with experience in the Justice Department,

running trials on the federal bench, judging trials, and in the U.S. Senate,

the only place that holds trials for a sitting president.

Also tonight, we have a special look at when a president was impeached for bringing, quote,

disgrace to the office.

I'm excited to tell you about that history.

But first, tonight, how does Congress assemble the evidence against the president?

Impeachment.

I never thought I'd see or hear that word with regard to me.

The president is not above the law.

It's a very serious meltdown on the part of the president.

You've got your facts wrong.

Rudy Giuliana was seeking out corruption.

You just describe it as a quick pro quo.

We do that all the time.

This is not a game for us.

This is deadly serious.

The This is not a game for us. This is deadly serious. We do it all the time.

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