“I urge you now also to remedy the harm done to the balance of powers by submitting the Iran Deal and the Paris Agreement to the Senate as treaties,” Cruz continued. “Only by so doing will the Senate be able to satisfy its constitutional role to provide advice and consent in the event any future administration attempts to revive these dangerous deals.”

Cruz has become a stalwart Trump ally, and if the president takes his advice, he could throw a wrench into the gears of the incoming administration before Biden can even fully nominate his Cabinet. The incoming president has promised that he would rejoin the Paris Agreement “on day one,” and pledged to revive the Iranian nuclear deal he helped negotiate as vice president. Republicans, meanwhile, are unified in their opposition to both.

A vote against them would signal GOP opposition to the world and, they hope, undermine any unilateral action by Biden to rejoin the agreements. One senior congressional aide told RCP that sending them to die in the Senate “would be the final nail in the coffin.”