President Obama and House Speaker John Boehner have had five years of fights and negotiations to learn how to work together.
The relationship has had ups and downs. Today it's as sour as it's ever been.
Even if they had a warm friendship, it might not be enough to solve the government shutdown. But the chilliness doesn't help.
'We Get Along Fine'
Their relationship has been a constant source of fascination in Washington. Interviewers ask the two men about it all the time. And they give pretty much the same response, year after year:
"I like the president."
"I like Speaker Boehner."
"We get along fine."
People who know both men say at various points in the past five years, these two have gotten along well enough.
Obama says Boehner reminds him of old-school Republicans he used to cut deals with in Illinois. Boehner, who smokes, has joked about the president chewing Nicorette.
They used to engage in good-natured public ribbing.
For example, at the White House Correspondents Dinner in 2009, Obama said: "After all, we have a lot in common. He is a person of color — although not a color that appears in the natural world."
Boehner echoed that theme on Fox in 2010: "First thing that'll happen is, you know, I'll come in and he'll say, 'Oh, Boehner, you're almost as dark as me.' We talk about golf; we'll talk about our skin color."
They're both avid golfers, and the two men played 18 holes together once, in 2011.
But when their relationship was seriously tested, it became clear that these two men are not wholly compatible.
From Grand Bargain To Disaster
In the summer of 2011, the U.S. reached the end of its borrowing authority — the same deadline the country is approaching later this month. Congressional Republicans demanded spending cuts in exchange for raising the debt ceiling.
Obama and Boehner both saw a chance for a legacy-defining deal — a grand bargain. Late night talks became marathon weekend sessions, culminating in disaster.
"It is hard to understand why Speaker Boehner would walk away from this kind of deal," the president said after the effort fell apart. Boehner, for his part, said, "The White House moved the goal posts."
Both men felt personally betrayed. Entire books have been written about what went on behind the scenes.
The upshot is that the relationship went from cordial to frosty.
As new crises unfolded, Boehner and Obama barely tried to find common ground. Last year, it was Vice President Joe Biden and Senate Minority Leader Mitch McConnell, the Kentucky Republican, who averted the fiscal cliff — two men who had known each other for decades in the Senate.
Boehner, meanwhile, openly mocked Obama on the House floor this week.
"I talked to the president earlier tonight," he said, then mimicked Obama: " 'I'm not going to negotiate. I'm not going to negotiate. I'm not going to do this.' "
It felt less like good-natured ribbing and more like someone impersonating an ex after a messy breakup.
On the same day, Obama told NPR that Boehner and other top Republicans are unsuccessful leaders, failing to stand up to renegade members.
"Right now they have been unwilling to say no to the most extreme parts of their caucus," Obama said.
Democrats and Republicans actually tend to agree on some of the reasons things have gotten so bad. For one, there's a basic personality trait. Neither Obama nor Boehner is a glad-handing extrovert.
"Boehner's not a warm and fuzzy guy," says former Democratic Rep. Tom Perriello of Virginia.
For his part, Republican strategist Ed Rogers says: "I don't know where Obama has formed a relationship that he didn't have prior to being president."
Both also agree that Boehner's burden has gotten steadily heavier over the past two years.
"The problem is, Boehner can't deliver his own caucus anymore," Perriello says. Rogers says the speaker "has to negotiate and then go back and seek consensus."
That tension means it may be impossible for the two men to cut a deal, even if they were best of friends.
But even if a warm relationship would not be decisive in this shutdown, a relationship of mutual suspicion and mistrust sure isn't helping.