On Tuesday, Sen. Ted Cruz (R., Texas) urged his Senate colleagues to reject a nuclear deal agreed to by the United States and Iran.
Cruz told Fox News host Greta Van Susteren that the deal is "catastrophic" for what it gives away to Iran.
After a 60 day review period, Congress will have to decide whether to go along with the deal. A supermajority coalition of Republicans and Democrats in both chambers will be required to kill the deal.
Cruz implored his colleagues, as well as the Fox News audience, to "stand up" for America by rejecting the deal.
"Everyone watching this should reach out to their members of Congress and say, ‘protect our national security,'" Cruz said. "To Democrats, don't use partisan loyalty to the White House. Stand up for the safety and security of America."
A number of Democrats have indicated they might vote against the deal, citing its opaque enforcement mechanism and sanctions giveaway to Iran.