(J. Scott Applewhite/AP)

Washington is not exactly renowned for its inhabitants' honesty. In the minds of Americans, politicians rank somewhere in the vicinity of used-car and snake-oil salesmen.

But it's rare that we see one week so full of contradictions, self-serving reversals, and proof that no principled stand is immune to changing partisan circumstances.

First there were Democrats mounting a filibuster against Judge Neil Gorsuch's Supreme Court nomination. In doing so, they suggested the 60-vote threshold was simply a long-standing fact of life, despite there being only one successful filibuster of a Supreme Court nominee and Gorsuch seeming to be well within the mainstream. And back in 2013, Republicans' regular filibusters of President Obama's nominees eventually led the Democrats to revoke it for non-Supreme Court picks — the so-called nuclear option.

Republicans also found the shoe on the other foot, going nuclear in their own right just three years after arguing that any mainstream nominee should be able to get 60 votes and that such a rule change was political gamesmanship gone way too far.

So basically, Republicans were apoplectic that Democrats would take something they did with such frequency to the next, logical step, and Democrats were apoplectic that Republicans would take what they did to the next, logical step.

And then President Trump decided to strike Syria, unleashing a whole new set of contradictions that also happen to date back to 2013.

Yet again, the situation was quite analogous to back then — the Syrian government allegedly using chemical weapons on its own people — but the roles were reversed for the president and the Senate. And the responses were just as different.

Back in 2013, nearly 100 congressional Republicans and a handful of Democrats signed a letter arguing that Obama needed to obtain an authorization for the use of military force (AUMF) in order to launch airstrikes in Syria as a response to the chemical weapons attack. And many others opposed the AUMF when Obama heeded the call for a vote.

As Politico's Kyle Cheney is documenting so well on Twitter, many of these Republicans are now cheering Trump's AUMF-free, unilateral strikes in Syria after another, less-deadly chemical weapons attack. And even some Democrats who were insistent upon the AUMF are conspicuously silent.

Trump himself is also a complete, 180-degree convert on Syria, after having also staked out a hard-line position against Obama involving the United States in its civil war and saying Obama needed to get an AUMF. Now Trump has responded to virtually the same situation with exactly the response he urged Obama against.

Plenty of ink has been spilled over the past couple of years on the flip-floppery of politicians. First and foremost in that conversation is Trump, whose true convictions have often been stated with the kind of certainty shown in the above tweets, only later to prove completely malleable and perhaps poorly thought through in the first place.

But while the degree and frequency of Trump's political evolutions may be unmatched, he's hardly the only one in Washington who will exit this week looking as if he doesn't have any principled and concrete beliefs about the most important political issues of our time. Perhaps going forward, every politician should qualify whatever they say by saying it only applies until power changes hands in Washington.