From what I understand from all the talking heads, "quid pro quo" seems to be a construct- the most convenient one at hand for the White House at the moment- and doesn't really need to be established to underscore the severity of what's already come to light. Based on the most current reading, there seems to be a consensus (from everybody not on the right side of the congressional aisle) that a sitting president pressuring a foreign head of state to dig up dirt on a political opponent is... pretty dang bad. As for Barr, at this point it's his word against the written transcript: Whether or not Barr ever followed up is maybe immaterial. As the head of the department that would have to work hand in glove with Congress on an investigation of this magnitude, Barr is demonstrably compromised.Mr. Giuliani is a highly respected man. He was the mayor of New York City, a great mayor, and I would like him to call you. I will ask him to call you along with the Attorney General. Rudy very much knows what's happening and he is a very capable guy. If you could speak to him that would be great.
I agree that what Trump did is bad enough. However, I expect that it wouldn't be enough for Pelosi to move so fast. She didn't even wait for the transcript before she announced. The fact that Trump tried to appease Pelosi so quickly, and the fact that he is holding a news conference suggests to me that there is another shoe to drop.