With a prospective nuclear agreement with Iran just days away, Senate Republicans are pushing the administration to drive a harder bargain - or walk away from a "bad deal."
Under the terms of an interim framework secured in April, the U.S. and five other nations agreed to lift sanctions on Iran in exchange for limits on Iran's nuclear activities and international inspections to ensure Iran isn't building a nuclear bomb. Negotiators are now working toward a final agreement by early July, a few days beyond the original June 30 deadline.
Lawmakers who have received classified briefings on the matter are now sounding the alarm about what that final deal might look like. They're particularly concerned about reports that the Iranians are demanding no international inspection of their military sites, and that sanctions could be lifted outright as soon as a deal is signed.
"I do feel it moving in a nonpositive direction," Senate Foreign Relations Committee Chairman Bob Corker, R-Tennesee, told Politico last week. "And I feel like one of my responsibilities is to share publicly those concerns, and privately."
"Knowing that the administration appears to be continuing to cross red lines that they previously have set, we want to point that out and hopefully stiffen their spines so the deal doesn't erode further," he explained.
Corker said it appears Secretary of State John Kerry, the chief U.S. negotiator in the talks with Iran, "really, really, really wants this deal." But the senator said he reminded Kerry, "John, it's just as much of a legacy to walk away from a bad deal."
The criticism from Corker is striking not only because he exerts a lot of control over the Senate GOP's tilt on foreign affairs as the top Republican on the Foreign Relations panel.
In the past, the Tennessee Republican has given more space to the administration's negotiations with Iran than many of his GOP colleagues. He did not, for example, sign on to a letter from Arkansas Sen. Tom Cotton to Iran's leaders that warned that any nuclear agreement between the U.S. and Iran would likely be short-lived.
Some Republicans who did sign that letter are voicing anxiety about the progress of negotiations as well.
"We're ceding to the Iranians, basically, over time," Georgia Sen. Johnny Isakson, who sits on the Foreign Relations panel, told Politico. "Every day, the Iranians have more of what they want and we have less than we want. From the briefings, I've got a lot of concern."
"It's going to be a disaster, this deal," added Wisconsin Sen. Ron Johnson, another member of the committee.
The administration has sought to calm fears, urging wary lawmakers to wait and judge the final deal instead of opening fire preemptively.
"To be sure, in any final deal, we'll be holding ourselves, and Iran, to the understandings we reached in" the interim framework, said Ned Price, spokesman for the White House's National Security Council. "All parties to the negotiation are well aware of what is necessary for a final deal, including the access and transparency that will meet our bottom lines. We won't agree to a deal without that."
And at least one Republican lawmaker says he's been heartened, not dismayed, by the progress of ongoing negotiations.
"Frankly, better," Arizona Sen. Jeff Flake told Politico when asked how he's feeling about the nuclear talks. "Nothing's final; we haven't seen any final agreement. But I'm encouraged."
Wherever lawmakers ultimately come down on the final text of the deal, it will be difficult for Congress to stop the administration from implementing a deal if one is reached. A bill passed in May gives the Senate the right to pass legislation disapproving of the deal with Iran, but the president could veto it, and it's likely Democrats could block any attempt to override that veto.
Still, it would be an embarrassment for the White House if a majority of the Senate goes on record opposing a deal with Iran. And if a GOP candidate wins the White House in 2016, the durability of that deal will be in serious doubt: many of the Republican candidates have vowed to overturn it if they're elected.
Also, last week, a bipartisan group of former diplomats, politicians and top administration advisers - including five from the Obama administration - wrote an open letter criticizing what they know of the agreement so far, stating that they "fear that the current negotiations...may fall short of meeting the administration's own standard of a "good" agreement."
And the group, which includes former CIA Director Gen. David Petraeus, former National Security Adviser Stephen Hadley, and Dennis Ross - who's worked in Middle East policy for three administrations - insisted on more aggressive language aimed at deterring Iran from building a nuclear weapon. So beyond what has already been agreed upon, they believe the agreement must also include "timely and effective access" to any sites deemed necessary by the International Atomic Energy Agency (IAEA); the ability to verify activity - including review of any nuclear weaponization activities; and limits on Iran's advanced centrifuges.