U.S. Sen. Bob Corker is walking a long, thin tightrope.
If he falls, it could badly bruise his political capital -- or America's reputation across the globe.
If he reaches the end, he could bridge a wide divide between Congress and the White House and create a unified American front to negotiations over any final nuclear agreement with Iran.
Corker told Chattanooga Times Free Press editors and reporters Thursday that having Congress and the White House on the same team would only help negotiations with Iran, who he said is "the largest exporter of terrorism in the world."
"I said to the president yesterday, this is positive for you, and it is positive for our country," Corker, who chairs the Senate Foreign Relations Committee, said of legislation that would give Congress a 60-day review of any comprehensive nuclear agreement reached with Iran.
But can he do it?
Vanderbilt University political science professor Bruce Oppenheimer said Corker seems to be sincere about capturing wide bipartisan support. But it won't be easy.
"It's very dicey. I think he's got a very tricky balancing act right here, and so far he's been able to walk this tightrope pretty well," Oppenheimer said. "But there's quite a ways to go yet."
To get his bill passed in the Senate, Corker has to find support from Republicans who are willing to work with the White House. And he must find Democrats willing to defy Obama, who Corker said Thursday "has been trying hard to kill it."
There's no doubt there's interest. By Wednesday night, senators had filed 144 amendments to the bill, Corker said.
Oppenheimer said if Corker's plan stumbles -- if it passes but the White House vetoes it, or the bill dismantles the seven-nation negotiations -- the senator risks his deal-maker reputation or his overall political clout.
"This is one area where you hate to embarrass an administration. What are you left with? Are you ignored?" Oppenheimer said.
Negotiators from China, France, Germany, Iran, Russia, the U.S. and the United Kingdom have until June 30 to reach a final draft of the Iran nuclear agreement.
Corker's bill aims to give the U.S. Congress 60 days to review and then approve or disapprove of the agreement -- at the same time preventing President Barack Obama from waiving heavy congressional sanctions against Iran. The bill also puts in place a requirement that the president report to Congress every 90 days on Iran's compliance -- and within 10 days of any violation of the agreement.
Jeffrey Lewis said what Corker's proposing is out of the norm.
Lewis is director of East Asia Nonproliferation at the James Martin Center for Nonproliferation Studies, a California-based organization that aims to combat the spread of nuclear weapons.
Past nuclear agreements with North Korea during the Bill Clinton and George W. Bush administrations never went to Congress for approval, he said.
And Congress typically gets only 60-day approval on peaceful nuclear cooperation agreements, which involve the international trade of nuclear materials for commercial, medical or industrial uses.
Disarmament deals usually are the purview of the president, Lewis said.
"Typically, Congress only has hearings, or Congress is asked to do specific things like rescind sanctions," Lewis said. "It would be nice to have congressional support, but at least as far as I see it, it would be unusual."
Corker acknowledged the effort was not typical but said the situation is exceptional.
"We know the 2nd Article of the Constitution," Corker said. "What you're seeing happen right now is a United States Senate that's saying that this is probably the most important geopolitical agreement that may occur while we are here. ... Bring it to us, let it lay before us for a reasonable amount of time."
Corker also said he doesn't want the deal with Iran to end up like past agreements.
"If you look at North Korea, we did these deals in North Korea and nobody paid attention," Corker said. "It's actually going to be the next president that will have to make sure Iran doesn't do what it's always done."
Should the bill pass, Corker needs a 68-vote supermajority in the Senate to block an Obama veto. On Thursday, Corker said the bill had much support from both sides of the aisle, but the number was fluid.
But Oppenheimer said Corker's real challenge will be in the House, where partisan politics are more rampant.
"He might be perfectly reasonable and then in the end the House does something that's partisan and unreasonable," Oppenheimer said.
Corker has at least one House supporter in a fellow Chattanooga Republican, U.S. Rep. Chuck Fleischmann.
"I am very appreciative of the work Senator Corker has done to ensure the White House does not bypass Congress," Fleischmann said in a statement Thursday. "It is important that both the House and Senate have a say in any deal that may come out of these negotiations and that the safety of the American people is put above all else."
The bill is up for a vote Tuesday in the full Senate Foreign Relations committee.
On Thursday, Corker said he knew there are some in Congress who would always oppose the president, and some who would always do his bidding. But he is appealing to what he sees as the majority in the middle.
"This is the time for ... the [other] 80 or 82 or 85 of us ... to conduct ourselves as senators on behalf of the American people," he said.
Contact staff writer Louie Brogdon at email@example.com, @glbrogdoniv on Twitter or at 423-757-6481.