At Wednesday’s rally against the Iran nuclear agreement, Senator Ted Cruz declared, “There are two men in Washington, D.C., who can defeat this deal. Their names are Majority Leader Mitch McConnell and Speaker John Boehner.”

The Iran deal is sure to be a major subject at next week’s Republican presidential debate, and it’s near-certain Cruz will repeat the charge. The question is whether any Republican on that stage will contradict Cruz.

In the view of the Obama administration, the Iran agreement never needed any congressional approval because it’s an “executive agreement,” not a treaty. The Supreme Court has given the executive branch wide latitude in determining what is a treaty, requiring ratification by the Senate, and what is just an “executive agreement.” Ideally, Republicans will push this issue back to the Supreme Court, because under the current interpretation, presidents will never need to get congressional agreement on any foreign agreement ever again. If the Iran deal doesn’t qualify as a treaty, it’s not clear what possibly could.

In the minds of Bob Corker and company, the Corker-Cardin deal — which passed 98 to 1, with only Tom Cotton voting against it — gave opponents at least a small chance of derailing the deal if they could get two-thirds of the Senate to oppose it. Of course, it was always a longshot to get Democrats to abandon their leader on his top foreign-policy priority — even when the stakes are nuclear.

(So long as the filibuster is in place, Republicans will need 60 votes to do what they want. They have 54, and four Democrats were willing to vote with them on the Iran deal, leaving them two votes short.)

Separately, as Andy McCarthy laid out, Speaker Boehner at least is pursuing other avenues of opposition:

The House strategy is now to pursue three resolutions: (1) finding Obama has not complied with the Corker law’s requirement that he provide the entire Iran deal to Congress — which he needed to do to trigger the review process; (2) barring Obama from lifting sanctions; and (3) proposing a certificate of approval (not disapproval) that would force Democrats who support Obama’s deal — which would provide over $100 billion to the world’s leading state sponsor of jihadist terror — to go on record.

Still, quite a few grass-roots Republicans feel their leadership on Capitol Hill is useless and hapless, and that with GOP majorities in both chambers, they should be able to at least get bills to the president’s desk. My guess is that Wednesday night, most Republicans on stage will eagerly insist they would be stronger leaders than McConnell and Boehner, and the two GOP leaders will feel like piñatas for most of the night.