It's worth remembering that fact at this moment as congressional Republicans find themselves confronted with a cavalcade of troubling news stories about President Donald Trump and his conduct in office. Because while elected GOP officials have almost totally capitulated to Trump's hostile takeover of their party, there is always a point at which you simply cannot look even quasi-objectively at the actions of this president and conclude that standing behind him remains the right (or even defensible) thing to do.

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And this week sure looks like just that sort of breaking point moment.

The most damning development is, obviously, the Tuesday testimony of Bill Taylor, the top US diplomat in Ukraine. Taylor's opening statement to Congress makes clear -- beyond any reasonable doubt -- that there was a quid pro quo organized by the White House: Announce investigations into Trump's preferred subjects (Crowdstrike, the Bidens) and get the military aid money being withheld.

"Ambassador Sondland told me that President Trump had told him that he wants [Ukrainian] President Zelenskyy to state publicly that Ukraine will investigate Burisma and alleged Ukrainian interference in the 2016 U.S. election," Taylor wrote at one point. (Burisima is a Ukrainian natural gas company; Joe Biden's son, Hunter, held a seat on its board for five years. There is no evidence of wrongdoing by either Biden.)

At another point, Taylor said: "President Trump did insist that President Zelenskyy go to a microphone and say he is opening investigations of Biden and 2016 election interference, and that President Zelenskyy should want to do this himself."

So........

The statement released by the White House in response to Taylor's bombshell testimony feels like it was written on another planet.

"President Trump has done nothing wrong — this is a coordinated smear campaign from far-left lawmakers and radical unelected bureaucrats waging war on the Constitution." said White House press secretary Stephanie Grisham.

But, like, what? Taylor was handpicked for this role by Secretary of State Mike Pompeo. Prior to that, he had spent decades in the diplomatic corps under Republican and Democratic presidents. He had retired before being personally asked by Pompeo to take over in Ukraine!

Plus, ask yourself this: Why would Taylor lie under oath? He so hates Trump -- despite zero evidence in his background that that's the case -- that he's willing to commit a felony? To what end?

If the Taylor testimony was all that happened over these last few days, that would be enough ! But, it's far from the only thing!

On Saturday night, he reversed a decision announced by acting White House chief of staff Mick Mulvaney just days before that the G7 conference would be held at his Doral resort in 2020.

And Trump continues to deal with the fallout from his decision to withdraw American troops from northern Syria, and Turkey's subsequent invasion.

But, but, but. The vast majority of congressional Republicans continue to stand behind Trump -- due in no small part to their fear that stepping out on a limb to say he needs to go (or even that the impeachment inquiry is the right thing to do) will lead to the President singling them out and ending their political careers.

Remember, however: Everyone -- everyone -- has a breaking point. And it's hard to see how at least some congressional Republicans aren't very near theirs after this week. And it's only Wednesday.