BY DAN VALENTI

Leaving Americans behind in a foreign country after an enemy of the United States swept to power and chased us out with our tails between our legs, though, is not likely to be forgotten, certainly not in 2022 or 2024, if ever.

The prime directive for any president is, to the extent possible, to seem in control. Biden failed this test repeatedly during the evacuation crisis. Events moved faster than he did and his rationales for what was happening had to be constantly revised, until he settled on the explanation that it is impossible to end any war in good order.

Privately, Democrats must know that his performances at his press conferences weren’t reassuring, let alone commanding. The problem Biden has is that any act of incompetence will, fairly or not, raise questions about his age, even if he would have done exactly the same thing at 38 that he he’s done now at 78.

The most notable feature of the resulting Biden drop in the polls that has him underwater in both the RealClearPolitics and 538 polling averages is his awful standing among independents. In a recent Washington Post/ABC News, he was at 36 percent approval among independents (and 44 percent overall). A new Economist/YouGov poll has him at 35 percent among independents (and 43 percent overall).

This isn’t a position of strength from which to deal with another structural problem that was submerged by his initial success getting new Covid spending and by wishful press coverage—uncomfortably narrow margins in the House and especially the Senate.

Biden can’t lose anyone in the Senate and only a handful of votes in the House, giving both the relative moderate wing of the party and its leftmost flank the ability to kill off his spending plans for being too profligate or too stingy, respectively.

Joe Manchin is a constant reminder of this. In recent days, he’s called for a “strategic pause” in the reconciliation process and has reportedly been telling people the most spending he’ll support from Biden’s signature $3.5 trillion proposal is $1.5 trillion. Both a significant delay and a much-reduced number could upset the delicate balance that Democratic leaders need to maintain to try keep all factions on board both the bipartisan infrastructure deal and the reconciliation bill.

Jonathan Chait of New York Magazine is, rightly, alarmed. “Even if Manchin doesn’t want to destroy Biden’s presidency,” he writes, “he may do so by setting off a vortex of failure he loses the ability to escape.”

Think about that—the fate of Biden’s presidency, or at last huge pieces of his domestic agenda, depends on a senator representing a Trump state who is largely immune to pressure from the national party, indeed may be helped if the national party calls him names for not going along with its priorities.

Even if Manchin doesn’t end up, deliberately or inadvertently, tanking the spending, Biden is going to have to devote a lot of time to grappling with his party’s highest profile moderate, who will be constantly making the case that the president’s current spending plans are too costly and irresponsible.

When all is said and done, Biden may get enough spending to allow Republicans to attack him as a wastrel and not enough spending to excite his own partisans, who have been primed to expect a Bernie Sanders-level budget.

Welcome to Biden’s reality. The heroic period of his presidency was always a mirage, and the effort to muddle through now begins in earnest.