President Trump's national security adviser Michael Flynn resigned Feb. 13 after revelations that he had discussed sanctions on Russia with the Russian ambassador to the U.S. prior to Trump taking office. Here's what you need to know. (Deirdra O'Regan/The Washington Post)

Michael Flynn's resignation as Donald Trump's national security adviser late Monday night proves that even for this most unorthodox of presidents, some of the old rules of Washington politics still apply.

Flynn — and the broader Trump administration — had been on defense for the last five days in the wake of a Washington Post report that Flynn had discussed recently-imposed economic sanctions with Russian Ambassador Sergey Kislyak, despite repeatedly denying having done so. Flynn denied it on the record to The Post and, more damaging for him, to Vice President Pence, who went on a Sunday show to assert that the sanctions had never come up in Flynn's conversations with the Russians.

Talk of Flynn's future dominated this weekend's political talk shows. The Post, New York Times and Wall Street Journal all ran stories raising questions about Flynn's ability to survive. White House counselor Kellyanne Conway told MSNBC Monday afternoon that Flynn “enjoys the full confidence” of Trump.

Shortly after, White House press secretary Sean Spicer seemed to contradict Conway, insisting that Trump was evaluating Flynn's future. Hours later, Flynn was gone.

What's remarkable about the Flynn saga was how incredibly routine it was. A deeply damaging story comes out. The White House goes into bunker mode. Conflicting reports from conflicting aides emerge. And then, whammo: resignation.

It was a prototypical Washington scandal that played out like hundreds of similar ones before it. It felt, dare I say it, normal.

Normal is worth noting in a presidency — and an administration — that has been anything but in its first 24 days. With Conway's statement Monday afternoon, it seemed as though Trump would again zig against the zag of conventional wisdom and keep Flynn on — refusing to give in to pressure from the political establishment and national media that he so reviles.

But Trump does value Pence. And he understands that Pence helps him in Washington and with the broader Republican Party. Although Flynn had apologized to Pence for misremembering — ahem — whether he talked about sanctions with Kisylak, Pence was still stung by the whole episode. Making Pence happy — and dispatching with a constant drip-drip-drip of negative headlines — trumped Trump's loyalty to Flynn. (Flynn was one of Trump's favored surrogates and often introduced the president on the campaign trail.)

What's remarkable about the whole episode is how unremarkable it actually is. The coverup is worse than the crime. Embarrassing the big bosses has major ramifications. Sacrificial lambs must be offered. The Flynn resignation had all of the beats of a traditional Washington drama. That made it very unique for this White House.