President Trump threatened to shut down the government over building his promised wall on the U.S.-Mexico border during a campaign rally in Phoenix on Aug. 22. (The Washington Post)

“If we have to close down our government,” President Trump said at his rally in Phoenix on Tuesday, “we’re building that wall.”

The crowd — loyal Trump supporters to a person — cheered wildly: “Build that wall! Build that wall!”

Since Trump took office, it’s been clear that his primary (if not exclusive) focus has been on delivering wins to his base of support, the people who powered him through the primaries and who still, despite his sliding poll numbers, will don a MAGA hat and show up at a rally on a work night. The wall is central to Trump’s promises to his base and to his identity as a candidate, and, so, if he has to shut down the government to get it, he’s going to get that wall.

In that context it makes sense. In the broader context of a president aiming to deliver for the American people (with an eye toward reelection) it doesn’t make any sense at all.

We’ve had a slew of polls on Trump’s wall proposal, and there’s a consistent theme to the results. Most people — Trump’s base excluded — don’t want the wall, don’t think the wall will happen, don’t think Congress will pay for the wall and, obviously, don’t think Mexico’s going to pay for it, either. (That claim that Mexico would fund the wall, an inescapable refrain during the campaign, wasn’t broached by Trump in Phoenix.)

Don’t believe me? Take a look:

From Fox News polling in May: Only 36 percent of Americans think a wall is going to happen, including 64 percent of Trump voters and 59 percent of Republicans. Twenty-nine percent of independents, 20 percent of Democrats and less than half of whites without a college degree — a key Trump constituency — think the wall will get built.


From that same poll: Even fewer Americans actually want the wall. About 3 in 10 respondents say they do want a wall, including 72 percent of Trump voters. But only 29 percent of independents and 6 percent of Democrats support the wall.


From a May Quinnipiac University poll: Only a quarter of Americans think that Mexico will pay for the wall. That includes a bare majority of Republicans, 6 percent of Democrats and 32 percent of whites without a college degree.


From a CBS poll earlier this month: Asked who would end up paying for the wall if it were built, more than 80 percent of respondents say the United States would pay for it. No group says Mexico would foot the bill.


But, then, a Fox News poll in June indicates that most people don’t think Congress is going to approve the funding that would be required to build the border wall. More than half of respondents say it’s “not at all” likely that Congress will approve funding, including one-third of Trump voters.


It’s not clear from the polling why people think it’s unlikely that Congress will budget funding for the wall. They probably understand that most Americans are not clamoring for it and that Trump’s campaign rhetoric was often occupying a space two houses down from reality. They’ve also seen Trump try to twist the arms of Congress to little avail.

It’s also not clear why Trump is taking this position on building a border wall. These numbers do not show the support you’d expect for a policy initiative that the president thinks is so important that we should allow the government to grind to a halt rather than not fulfill his campaign pledge. (Not that allowing the government to shut down is a normal tactic for a president.)

White House press secretary Sarah Huckabee Sanders was repeatedly asked on Aug. 24 if President Trump was reneging on his campaign promise for Mexico to pay for a border wall, a day after President Trump's threat to shut down the government over funding its construction. (Reuters)

It’s certainly possible that Trump plans to use the wall as a rallying cry for years to come, much as Republicans did the “repeal-and-replace Obamacare” mantra that was revealed as hollow a few months ago. Trump told his base that he’d build the wall and that Mexico will pay. Many of them believed him, and, polling suggests, they’re the only ones who did. If he says today that he’ll shut down the government and make the wall happen, why would they doubt it now? If he spends three more years blaming Republican leaders in Congress for the lack of a wall, why would that prompt new suspicion?

And if the wall never gets built, that’s probably not going to make Trump’s future electoral prospects any worse.