You’ve seen the letter by now, or at least heard about it, the one sent from the GOP’s Tehran 47 to the Iranian mullahs.

The one signed by 47 Republican senators, including McConnell and Paul and Cruz and Rubio and our own Cory Gardner.

The one designed to undercut/sabotage/debase the president of the United States in the eyes of our longstanding enemies, not to mention our closest allies, even as the Obama administration nears the end game in negotiating a nuclear deal with Iran.

The one that is pretty much unprecedented — you know, in the way that inviting a foreign head of state to rip Obama in a joint session of Congress was pretty much unprecedented.

The one that basically says to the Ayatollah, look, do what you need to do, just don’t give an inch to Obama, because, after all, we never would.

The one that purports to be a constitutional advisory that (according to Harvard law professor Jack Goldsmith) gets a major chunk of the constitutional part wrong.

The one that goes out of its way to talk down to the Iranians, who, the signatories worry, aren’t sharp enough to understand the Constitution but who are apparently smart enough to make a bunch of nuclear weapons and the missiles to deliver them.

Yeah, that letter.

Read it again, and then ask yourself this question: Who do you think these senators have humiliated, Obama or themselves?

Let’s give the 47ers the benefit of the doubt. Let’s say that the letter just looks like a demented attempt for Republican senators to ally themselves with Iranian hard-liners in order to deal Obama a defeat, but is in actuality a desperate attempt to save America from what they think is a terrible deal (one that that would, if it works, possibly ensure that Iran doesn’t get a bomb for at least the next 10 or 15 years).

If we concede all that — and I wouldn’t, but I’m ready to listen to the argument — it still looks like a disaster for the Republicans.

As Brian Beutler argues in the New Republic, if the Iranians were to take the letter seriously — which is unlikely, but, again, let’s concede the point for now — they would be more inclined to make a deal immediately, rather than holding out for something better. Because, according to the letter, nothing better is ever coming.

In other words: If Iran’s leaders ever want to get paid off for not making a bomb, they should take the deal as offered. I don’t think John Kerry could put it any better.

What’s curious is trying to decide what exactly the letter writers want the Iranians to do. I’m pretty sure they don’t actually want Iran to have the bomb, any more than I think they believe Obama wants Iran to have the bomb. But let’s break down the logic: If Iran doesn’t take the deal, the West imposes tougher sanctions. If the mullahs don’t want tougher sanctions, they make the deal. If they are prepared to live though tougher sanctions, though, their only possible payoff is to build the bomb.

The letter makes clear, in case the Iranians misunderstand, that Obama is near the end of his term-limited two terms and that senators can be around forever (as if that were possibly a good thing). They actually explain the six-year and four-year thing like we were all back in Jeffco-approved AP U.S. History, wherein all the endings are happy, including the part about getting rid of Obama.

And then there’s the money paragraph:

“[W]e will consider any agreement regarding your nuclear-weapons program that is not approved by Congress as nothing more than an executive agreement between President Obama and Ayatollah Khamenei. The next president could revoke such an executive agreement with the stroke of a pen and future Congresses could modify the terms of the agreement at any time.”

Yes, we’re back to executive authority and why this Congress never seems to have its way with Obama. But the Iranians should know that Obama will soon be gone, and then look out, because possible future President Bush/Paul/Walker/Cruz/Rubio/Huckabee/Christie/Carson/etc./etc. will let them have it.

Except this argument doesn’t hold up any better than the previous arguments. Let’s say Iran agrees to the deal with the United States and its negotiating partners. Let’s say that Iran follows the terms of inspections because the Ayatollah has no other option.

Which future president, Republican or otherwise, is going to overturn that plan? The only way this open-letter threat would convince Iran not to take the deal is if Iran already plans to sabotage the deal.

And so we’re left with a clumsy anti-Obama scheme — one that leaves Republicans open to the charge that they’re undermining our foreign policy — that has provoked Democrats, confused our allies and amused the mullahs. If you don’t get the sick joke, just read this closing paragraph:

“We hope this letter enriches your knowledge of our constitutional system and promotes mutual understanding and clarity as negotiations progress.”

I’d say it’s the most we could hope for.