Washington (CNN) It's hard to imagine how the past three days could have gone worse for Republicans.

The public impeachment hearings were never going to be a good thing for Trump -- given that the proceedings were controlled by the House Democratic majority and we knew, from a series of closed-door depositions over the past month, that the witnesses who would be called had a) expressed deep misgivings about President Donald Trump's phone call with Ukrainian President Volodymyr Zelensky on July 25 and b) suggested that there was a not-so-secret quid pro quo in place that unless the Ukrainians announced an investigation into Joe and Hunter Biden they would not get the White House meeting with the President they so desired.

But even by those standards, what happened over the past 72 hours was a disaster the likes of which not even the most pessimistic Republican could have predicted.

The Wednesday testimony of US Ambassador to the European Union Gordon Sondland was obviously the pivot point of the week. Going into Sondland's testimony, no one was quite sure what he would do. Spill the beans? Plead the Fifth? Something in between? Sondland, who was one of the witnesses that Republicans had pushed for, wound up opting to save himself -- at the expense of everyone from presidential lawyer Rudy Giuliani to Secretary of State Mike Pompeo to the President himself.

Sondland's opening statement is one for the history books, as he made clear that not only was there an understood quid pro quo (a White House meeting in exchange for Zelensky announcing an investigation into the Bidens) but that everyone in the Trump inner circle was entirely up to speed on it.

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