When President Barack Obama was seeking House votes for an ill-fated climate change plan in 2009, I was summoned to Capitol Hill for a ritual flaying.
Democratic House members were rightly anxious about casting a politically fraught vote, particularly without any assurance the Senate would take it up. (It didn't.) So I was sent from the White House with the dubious assignment of making the political case to the Democratic caucus for the hazardous vote.
The moment I walked through the door, and before I addressed the group, the once and future Speaker of the House Nancy Pelosi accosted me. "The President of the United States assured me that he would be out, making a public case for this vote," she said, jabbing a finger in my direction. "Where is he?"
Mercifully, God intervened. A clergyman took to the microphone, causing Pelosi to pause the tongue-lashing as she bowed her head and clasped her hands in prayer. But as soon as amens were said, she resumed her tirade.
"And if I don't see him out there, I am going to pull this bill!"
Pelosi was Obama's greatest and most resourceful ally on Capitol Hill. She was tough and unsparing, even to a friendly White House, when the moment demanded.
Newly back in charge of the House, Pelosi has just treated President Donald Trump to a brutal civics lesson about the separation of powers under the US Constitution. Friday, the President called an end to his five-week partial government shutdown.
Now both he and Pelosi have calculations to make.
The most urgent are those of Trump, who impulsively painted himself into a corner and smashed headlong into his mythic border wall. Picking a fight he could not win, he neither pleased his base nor the majority of Americans who reject the wall and resented the costly, marathon shutdown.
In Pelosi, Trump has encountered a canny and implacable foe, with an intimate understanding of the power invested in the Congress. She would not be bullied or cowed.
It seems doubtful that the speaker, flush with victory, will extend a life raft to the President, who faces another deadline three weeks from now. It is unlikely that her caucus will yield on the wall; instead it will probably offer the same package of border and port enhancements it proffered last week.
Had he not made the wall his sine qua non, Trump might have been able to claim this as a victory, arguing that he won significant new funding for border security. After all, he may not be the master negotiator he played on TV but the man does know how to sell.
The problem is, he got elected by selling the wall. He invested it with huge symbolic importance and his faithful, nativist flock believed him. They saw his capitulation on the shutdown as surrender. He is their leader. They are his jailers.
So my guess is that Trump will play the national emergency card when the deadline arrives in three weeks, claiming the power to shift funds from other purposes to build the wall.
He almost certainly will lose again -- this time in the courts -- as the Constitution clearly assigns the power to appropriate money to the Congress. But he will want to get caught trying, in the eyes of his followers. The judges will become his foil.
Trump's bigger concern should be less a wall on the border than the ones closing in on his presidency. On the very day he paradoxically declared victory in the shutdown battle by signaling surrender, he saw another ally ensnared in a Russia probe that seems to be churning to a crescendo.
With the indictment of Roger Stone, special counsel Robert Mueller added another piece to a jigsaw puzzle that is taking shape. And no matter how often the President loudly proclaims "witch hunt" and denies collusion, the growing weight of evidence dispels both.
The House will have the responsibility to act on Mueller's findings or any attempt by the White House and Justice Department to suppress them. No one knows exactly what the inscrutable special counsel will conclude.
But for two years, Congress has done its best to shield Trump from a thorough reckoning on Russia, his commercial exploitation of the White House and myriad other potential abuses.
Now the power of the House is in Pelosi's hands.
What should be clear to the President today, if it wasn't before, is that she knows how to use it.