president saying to zelensky, i'll give you the aid if you start this investigation is the president trying to bribe zelensky into a corrupt act. the investigation into his rival, by giving him asking that is an official act from trump, that trump is trying to then withhold. >> and, indeed, when the speaker came out and used the b word, bribery, that's the point they're trying to hammer at. >> that's exactly right. part of the reason they're focussed on this question is the explicit thing to say the president can't engage in bribery, which they understood as using the powers of the office for your own personal benefit. >> and katie, is there any peril to the president continuing to take shots at witnesses in real-time, which he did during the mueller investigation, let's not forget. >> absolutely. and every time he does that he puts himself in more peril. so we saw with the ambassador to ukraine, he tweeted about her and he said things that she felt were threatening and adam schiff said we take witness