WASHINGTON — As Donald Trump approaches the 100-day marker of his first year in office, he has defined himself not as the Dealmaker in Chief but as The Backdown President.

What a deliciously strange irony that until Monday night he set the stage for a government shutdown over, of all things, his campaign centerpiece — The Wall.

Strange because Trump, who now calls the faux deadline “ridiculous,” promised so much by his 100th day. Delicious because everything Trump does is scrumptious, especially eating chocolate cake while launching real missiles.

And it was always clear to perennial observers of Washington’s sausage factory that the new president’s ambitions exceeded the pace and will of the nation’s political class. Today’s Republican Party may control the executive and legislative branches, but its members are hardly trilling in harmony, thanks to the too-rare interference of mental clarity.

The wall may have bestirred the passions of Trump’s base — recently represented at the White House by that classy trio, Sarah Palin, Kid Rock and Ted Nugent, who managed a convincing imitation of cowpokes at the Ritz by mugging beneath a portrait of former first lady Hillary Clinton — but its construction wasn’t exactly a national mandate.

The only person to place this fantasy in proper perspective was former Mexican President Vicente Fox, whose succinctness was an elixir for the babble-weary. Clenching his teeth, he said, “We’re not going to pay for that [expletive] wall.”

Next thing you know, Trump was asking Congress to include billions of dollars for the wall in an omnibus bill, which must be passed by Friday to keep the government running. He wanted $1.5 billion for this fiscal year, which runs until September, and another $2.6 billion in 2018. Democrats said no way, and some Republicans also balked.

After all, the whole premise of the “big, beautiful wall,” later amended to, perhaps, fencing in “certain areas,” was that Mexico would pay for it. So familiar was Trump’s wall trope that during rallies, he’d bait crowds with Who’s going to pay for it? Mexico!

This was fun for the crowds, but also rather absurd, some of us noted, repeatedly. The disconnect between the witty and the witless was that Trump fans took him seriously, not literally, while the media — silly gooses — took him literally but not seriously — as many have mentioned.

This is a clever observation, but it’s ludicrous to suggest that reporters shouldn’t take literally a president’s or candidate’s words. Certainly other nations and leaders do.

Trump himself, however, seems to take his own words neither literally or seriously, as his backtrack record suggests. On Monday, he walked back his demand that wall funding be included in the bill, saying that he was open to delaying funding until September. No doubt, his White House aides reminded the president that un-funding the government doesn’t usually work out well for the majority party.

During Jimmy Carter’s presidency, the government was shut down five times for brief periods, mostly over abortion-related issues. Ronald Reagan, who sauntered in and enjoyed credit for the release of the Iran hostages, was the right cowboy at the right time. In more recent memory, the 2013 shutdown, orchestrated by tea party Republicans and instigated by Sen. Ted Cruz, resulted in at least some midterm losses for the party. Notably, Republicans lost the governor’s seat in Virginia, where a sizable number of federal employees live.

Two years later, with a promise to drain the swamp and build a wall between the U.S. and its southern neighbor, Trump oozed down his escalator to capture the imaginations of both the unemployed and the corporate expats who failed them. Endowed with the panache of Howard Stern and the moral vigor of a man who boasts about grabbing women by their nethers, he convinced fewer people than voted for his opponent that he was the right clown for the right rodeo.

To each his own, I suppose.

As for the wall, Trump’s campaign trope was repackaged awkwardly in a Sunday tweet as “Eventually, but at a later date so we can get started early, Mexico will be paying, in some form.” Hardly a rallying cry, but at least we’re spared another partisan war — for now.

Americans, meanwhile, have learned three lessons: The best things happen when The Backdown President retreats; we, and not Mexico, will be the ones footing the bill for the wall, if ever it is built; and Trump, in just under 100 days, managed to bring the government close to crisis on a promise that was always a con.

Kathleen Parker’s email address is kathleenparker@washpost.com.