THE Chattanooga Rotary Club, a hub for good works in Tennessee’s fourth-largest city, had a busy start to April. At their lunch meeting on April 9th members paid tribute to a deceased colleague and discussed a school tennis contest that they sponsor. Then came a briefing from Senator Bob Corker, the Republican chairman of the Senate Foreign Relations Committee, about Iran’s suspected nuclear-weapons programme, diplomatic efforts to constrain it and the very large bombs that America has built to drop on Iranian bunkers if all else fails.

Mr Corker, who was mayor of Chattanooga before being elected to the Senate in 2006, acknowledged a certain incongruity. A multi-millionaire businessman (he began his career adding drive-in windows to burger bars and ended up building shopping centres in 18 states), he normally talks taxes and spending to Rotarians. But the softly drawling 62-year-old has spent weeks at the centre of a geopolitical drama, leading a push to give Congress a say over American nuclear diplomacy with Iran. The task required overcoming years of painful history between the main actors, involving mutual distrust, fiery bombast and paranoia (but enough about Barack Obama’s relations with Congress).

On April 14th Mr Corker pulled off a rare victory for bipartisan compromise: a unanimous vote in his committee backing a bill that gives Congress at least 30 days to review a final accord with Iran, and the right to approve the lifting of those sanctions on Iran that Congress originally imposed. The White House stepped back from threats of a presidential veto. Republican hawks held their fire on amendments designed to blow up the deal.

How did Mr Corker do it? People believe that he is sincerely trying to keep party politics out of foreign policy. A change in the committee’s leadership helped, too: Bob Menendez, a Democratic hawk, was indicted for unrelated corruption and has temporarily stepped aside. A figure close to the talks calls Mr Corker “straightforward”. The same source concedes that growling from Congress was useful during months of nuclear wrangling, with officials from America and Iran comparing notes about who faced greater pressure back home. Yet the White House hated Mr Corker’s bill as first drafted, saying that it might become a vehicle for senators determined to undermine the nuclear talks.

Mr Corker is a fan of transparency. He offered Chattanooga Rotarians a briefing full of wonkish detail, down to centrifuge statistics, specific Iranian nuclear sites and their vulnerability to bunker-busting munitions (he skipped the classified bits). His candour extends to admitting that neither party has a monopoly on wisdom. Mr Corker described a world full of dangers, from the Middle East to Ukraine and the seas of South-East Asia. Unlike many Republicans, he did not seek to blame that entirely on Mr Obama. Indeed, responding to a question about turmoil in the Middle East, he noted that it predates this presidency. He told the crowd that by invading Iraq in 2003 “we took a big stick and beat a hornets’ nest”, unleashing regional and sectarian rivalries that may take decades to resolve. That is common sense, but not all politicians are as honest.

In Chattanooga the approach works. The Rotarians were a mostly conservative crowd, with little love for Mr Obama. Yet rather than wanting their senator to fight the president at every turn, there was much talk of trusting Mr Corker. Several Rotarians independently volunteered that Tennessee has a history of sending pragmatic “statesmen” to the Senate.

Everything you want to know about the nuclear deal with Iran There is pride, too, at all the attention being paid to their former mayor, even if some coverage rings false. The meeting laughed at a Washington Post report read aloud by its moderator, calling the senator “mild-mannered”. Chattanooga prefers such terms as single-minded and driven. A close local ally says of the senator—more or less in the same breath—“I love him” and “I have never known any human being like him in my entire life. He is a crazy man.” This, it turns out, is a compliment. Throughout his career, the ally explains, Mr Corker has latched onto subjects and made himself indispensable by mastering them, devouring specialist texts and quizzing experts until they are “begging” to be left in peace. In his own telling Mr Corker knew little about foreign affairs before entering the Senate. He set about making mostly solo trips to more than 60 countries, eschewing large congressional delegations. In one-on-one meetings with foreign leaders “the conversations are different”, he says.

Advice and consent

Mr Corker is not a centrist. He often despairs of Mr Obama’s foreign policy. Notably he says the president made a “massive mistake” in 2013 by failing to enforce a red line that he had drawn against the use of chemical weapons by Bashar Assad’s regime in Syria. Vladimir Putin in Russia “took great note”, as did unhappy allies, Mr Corker thinks. He says he cannot look refugees from Syria in the eye again: America made so many promises that were never kept. He and Mr Obama have had “terse” conversations about all this. But he did not join the 47 Republican senators who sent an open letter warning Iran’s leaders against doing a nuclear deal without the approval of Congress, saying that missive was not “productive”.

Senator Tim Kaine of Virginia, a Democrat on the Foreign Relations Committee, says he urged the White House to accept that Congress was going to weigh in on Iran, and it would either be a debate or a “free-for-all”. Senator Jeff Flake, a Republican committee member, thinks the White House should see that Mr Corker is as fair a chairman “as they can expect”. Support for an Iran deal from the full Congress is still not a given—though if Mr Obama cannot convince the 34 Democratic senators he needs to uphold a presidential veto, he might like to ponder what is wrong with his diplomacy. Mr Corker has shown that a reasonable man can get stuff done, even in an unreasonable town.