American politics has become famously tribal, but one of the hottest Senate contests this cycle is notably not: the race to replace retiring Sen. Bob Corker (R) of Tennessee.

Senator Corker, influential chairman of the Senate Foreign Relations Committee – and once again an ally of President Trump – is a longtime friend of former Tennessee Gov. Phil Bredesen, who is running for Corker’s seat and leading in the polls.

Here’s the rub: Mr. Bredesen is a Democrat. And Corker has no intention of campaigning against his friend, or (by implication) for the Republican, Rep. Marsha Blackburn. Corker, in fact, was so concerned that the very conservative Congresswoman Blackburn would lose his seat that a few months ago, he floated the idea of running for reelection after all. But he didn’t.

Now, the latest poll out of Tennessee shows Bredesen ahead of Blackburn by 10 percentage points. And this race matters. Republicans control the Senate by the slimmest of margins – 51-49.

But Corker is adamant. He will not campaign against Bredesen. He has donated the maximum allowable to Blackburn’s campaign, but that’s all he’s done for her.

“Look, I’m not going to campaign against someone who I’ve been a friend with and worked with,” Corker said Wednesday at a breakfast for reporters hosted by The Christian Science Monitor.

Michael Bonfigli/The Christian Science Monitor Sen. Bob Corker (R) of Tennessee talks with reporters at a Monitor breakfast at the St. Regis Hotel in Washington on April 18.

Corker talked about his and Bredesen’s 23 years’ worth of collaborations. When Corker was Tennessee’s commissioner of finance and Bredesen was mayor of Nashville, they worked together to bring the Titans football team to the state. Later, as senator and governor, they worked together to bring Volkswagen into Tennessee.

Corker says that poll may be a little “heavy” for Bredesen, and suggests it’s more like a six-point lead. But that’s still significant, in a state that candidate Trump won by 26 percentage points.

“Will Bredesen have crossover appeal? No question,” Corker says. “I mean, you know, we have significant Republican fundraisers who are hosting fundraisers for him today.”

Corker, in fact, has a healthy campaign war chest of his own – $6 million. What might he do with it? “I have absolutely no idea,” he says. “But I certainly don’t plan on dispersing it anytime soon.”

Corker also takes pride in his state’s history of producing distinguished senators.

“Let’s take me out of the picture,” he starts. “There’s something in the water in Tennessee.”

Corker rattles off illustrious Volunteer State senators from both parties: Howard Baker (R) – majority leader, White House chief of staff, US ambassador to Japan; Al Gore (D) – vice president, presidential nominee; Bill Frist (R) – majority leader; Jim Sasser (D) – US ambassador to China; Fred Thompson (R) – Watergate attorney, TV actor, presidential candidate.

Tennessee’s senior senator, Lamar Alexander (R) – who, like Corker, has a record of bipartisanship – has also served as governor and US secretary of Education, and ran for president twice.

“We’ve had senators that, generally speaking, have been statesmen, that are willing to burn political capital to solve our nation’s problems, and are thoughtful people,” Corker says. He hopes “both candidates present themselves in this race as people who are going to be willing to do that.”

Corker has had well-publicized ups and downs with Trump. During the campaign, Trump reportedly had Corker on his short list for running mate, then after winning the election, considered him for secretary of State. By last fall, the two were on the outs, with an exasperated Corker tweeting about the White House as “an adult daycare center.” Trump tweeted back about “Liddle” Bob Corker, mocking the senator’s slight stature.

By January, Corker and Trump had mended fences, and now they talk regularly. At the Monitor breakfast, Corker applauded Trump’s “accessibility,” though he noted that there’s a downside. Trump talks to people on the phone late into the evening, and by morning, he might have a completely different position on an issue that staff and allies had thought was settled.

Still, Corker says he now has a good working relationship with Trump, which leads to an obvious question: Would the senator take a position in the Trump administration after he leaves office at the end of the year? How about chief of staff?

“Conjecture is bad for your health,” Corker says cryptically. “I go to bed early, too.”

John Geer, a political scientist at Vanderbilt University in Nashville, calls Corker a “class act.”

“He is smart and wants to make a difference,” Professor Geer says. “He has had some disagreements with President Trump. But that speaks to his independent streak. It will be interesting to see what he does next.”