WASHINGTON — This must be the last shutdown, ever. No politicians should be able to wreck government and inflict suffering on its employees as a form of brute force to get their way.

Any deal to end this nonsense must therefore include a measure akin to the no-more-shutdowns proposal from Sen. Mark Warner, D-Va., disarming those who so disrespect government that they’re willing to throw the country into chaos.

It also means that continuing to resist President Trump’s intransigence is not a radical position. It is the moderate position.

There is longing for “moderates” of one kind or another to come up with a solution to this crisis. Yet what’s more moderate than saying that everything related to border security should be on the table for negotiation, but in a considered, thoughtful way? A border wall should not be privileged just because we have a president obsessed with symbols that rally his base.

And, by the way, that base is shrinking, as a CBS News poll released on Wednesday showed.

The pollsters asked: “Do you think the issue of a border wall is worth the federal government shutdown or not?” Overall, 71 percent of Americans said that the border wall is not worth the shutdown, including 92 percent of Democrats, 71 percent of independents and 43 percent of Republicans. GOP senators facing Thursday’s scheduled votes on competing proposals — with and without Trump’s $5.7 billion in wall money — should note that this fight is uniting Democrats and dividing their own party.

Let’s be clear: Trump’s opponents are not refusing to negotiate. In fact, House Democrats said on Wednesday that they’re willing to offer additional money for border security, though not for the wall.

As Sen. Tim Kaine, D-Va., said Tuesday in an interview with NPR’s Rachel Martin: “Democrats — I certainly am, and my colleagues are, too — are glad to have the discussion about the elements in the president’s proposal.” All they are asking, he said, is to “treat it like every other item of business we have, rather than a take-it-or-leave-it.”

In other words, don’t let Trump use a shutdown to override the normal process of governing. “[Republicans are] saying people’s lives are the leverage they want to use, and we want to discredit the use of government shutdown as a negotiating tactic,” said Sen. Tim Kaine, D-Va.. “Why take paychecks away from FBI agents? Why shutter food-stamp offices because the president’s not getting his way on border security?”

Why, indeed?

And Trump has shown that negotiating with him is a fool’s errand. His proposal last Saturday was presented as a “compromise.” It was no such thing. His “concession” to legalize — temporarily — the status of some 700,000 immigrants brought across our borders when they were children essentially ratifies the status quo forced on Trump by lower-court decisions that the Supreme Court left in place on Tuesday.

His supposed step toward more openness for asylum seekers turned out to be exactly the opposite, once its more stringent provisions were made clear. Trump’s approach to negotiating is: Give me what I want, and if you don’t, I’ll ask for even more.

This is lunacy. It has to stop, which is why Warner’s end-shutdowns bill is so important. As The Washington Post’s Aaron Blake summarized it: “In the event of a lapse in government funding, the act would reinstate funding levels from the previous fiscal year — except for Congress and the office of the president, which would not receive funding until they reached an agreement.”

Warner calls his bill the “Stop STUPIDITY Act,” standing for “Shutdowns Transferring Unnecessary Pain and Inflicting Damage in the Coming Years.”

Trump wants rational people to be so horrified at the damage he’s willing to inflict that they’ll cave in. It’s his M.O., as Damian Paletta and Josh Dawsey noted in The Post: “He creates — or threatens to create — a calamity, and then insists he will address the problem only if his adversary capitulates to a separate demand.”

Giving in to such behavior is not moderate, reasonable, or sensible.

What would be moderate is a suggestion from my friend, former Capitol Hill staffer Bruce Wolpe — reopen the government and name a bipartisan commission to assess border and immigration issues, with a 60-day deadline to report.

Yes, Congress regularly resorts to commissions when government seems paralyzed. But with the president assuming the mantle of paralyzer-in-chief, we need a resolution that does not empower a leader so selfish he’s quite happy to tear our government apart, piece by piece.