If the jury doesn't believe what Gates is saying, then Mueller's case is in real trouble. Even the judge pointed out obvious lies Gates has been responsible for in the past.

Maybe I'm a little jaded, but my opinion is that Gates has not come across as a reliable witness, and this is a big problem for us. I hope I'm wrong.

and he wasn't completely forthcoming... it could be evidence that he lied after getting immunity.

That voids his immunity deal and could make the rest of his testimony suspect.

Fortunately the case against Manafort is based almost entirely on document evidence... not the testimony of Gates or any other person.

Where it came from and where it went.

So the defense is pointing out that he is a scumbag. The thing is there is a paper trail to support the things he is saying against manafort in his testimony.

If everyone around you is corrupt and immoral, and you're the one common denominator - well, maybe all our exes have a point.

He only want to hamper the prosecution's case.

The defense is allowed to suggest that the witness is not credible and should not be believed. "He'll lie to his wife so why would you not think he'd lie to the jury?".

From my point of view, the best response is that if he lies here, he loses his deal with the prosecution, with whom he has already plead guilty. The wife didn't have that kind of clout. And the prosecution can check his testimony against a rather large amount of actual data and emails.

Lots of people have affairs. Paul Manafort was having an affair. Donald Trump has had many affairs that he's bragged about. Bill Clinton had affairs. Who cares?

Gates is but one small piece of the case against Manafort. It's pretty weak sauce to say he's not credible because he admitted to an affair. In my view, his admission makes him more credible as a witness. Additionally, his significant testimony about the business and financial dealings he had with Manafort are all backed up by documentation.

Gates' credibility shouldn't be a problem. Manafort simply has no defense so they're reaching for any straw.

To indicate he's the type to lie and cover up, I guess (and perhaps why he needed even more money). And if the prosecution will use that against the accused, I suppose they have to say it can be brought up about prosecution witnesses too.

Stealing millions and defrauding the government just doesn’t enough poor character. But affairs? OMG!