A “staggering betrayal” is how one pro-Israel activist in Washington describes any use by the Democrats of a filibuster to prevent the Iran deal from getting a full vote next month in the Senate.

That is emerging as the goal of the backers of President Obama’s contract with the mullahs. They want to block the measure from getting a vote in the Senate at all, which would leave Obama with a free hand to release billions to the Tehran regime.

The activist, Omri Ceren, who is The Israel Project’s managing director and has been working the story for months, says that would be a “stab in the face.” He notes that “Americans by a 2-1 margin want Congress to reject the bad Iran deal.”

The pro-Israel community, he says, has “worked in a bipartisan fashion with Congress to give the president breathing room for negotiations while protecting legislative prerogatives.” He thinks the Senate Democrats therefore owe Americans an up-or-down vote.

As this drama drags on, however, it’s not all that clear that we’ll see that vote. For it to take place, 60 senators must agree to cloture. At the moment, the Washington Post counts only 57 senators against or leaning against the deal.

This could change, of course. Only 33 senators are for or leaning for the deal. That leaves 10 undecided. If it does go to a vote, and the Senate votes to reject the pact, the president could veto it. At that point, even more votes against the deal would be needed to override. So it’s none too soon to think about what happens after.

One possibility is a round of recriminations among supporters of the Jewish state. Did Prime Minister Netanyahu misplay his hand? Did the American Israel Public Affairs Committee blunder by announcing a multimillion-dollar lobbying campaign?

Already some are complaining that such a boast energized Iran’s supporters. For my part, I wouldn’t waste a New York nanosecond on that kind of handwringing. No opponent of this deal — least of all Israel’s elected leadership — is going to owe anyone an apology.

Moreover, if Obama fails to win a simple majority of either the Senate or the House or both, a startling situation is going to emerge. The administration is going to have to implement a pact that voters couldn’t block but still oppose.

That would be a ghastly situation for the Democrats — worse even than what happened after SALT II, the arms pact President Carter inked at Vienna with the Soviet party boss, Leonid Brezhnev, whom the American president kissed at the signing.

Mr. Carter ended up withdrawing the treaty from consideration in the Senate, where it stood no chance of ratification. SALT II was one of the reasons Mr. Carter lost the next election to Ronald Reagan (who honored the treaty only until the Kremlin violated it).

The Iran accord is different from SALT II, in that the Iran pact is not being submitted as a treaty. The whole constitutional setup, which is supposed to put the burden of proof on the president submitting the treaty, has been turned on its head.

In this deal, not only the Senate but the House must muster the votes to block the deal or it goes through automatically. If a resolution of disapproval is then vetoed by Obama, the deal still goes through.

But if Obama is left with a deal that is opposed by a majority of either the Senate or the House, the Democrats will be stuck with it. They will then be on the defensive with every hostile move Iran makes with the $150 billion the mullahs are going to get.

No doubt they’re going to try to skate through it. Israel’s Haaretz newspaper has reported an amazing lack of reaction by the Obama administration and others to rocket attacks from Syria that last week struck northern Israel and that were initiated by Iran.

Those rockets are but a wake-up call to what lies ahead, just in time for a presidential election. That’s the next big fight if this deal goes through, defeating the candidate of the Democratic Party that appeased Iran. Staggering betrayal, indeed.

This column first appeared in the New York Post.