If Senate Republicans are hoping Sen. Tom Coburn (Okla.), one of their fiercest ideologues, is going to help them take on President Barack Obama on health care reform, they may not want to hold their breath.

While Coburn has plenty to say about the president’s proposals, he says he isn’t going to play the partisan attack dog this time. That’s because when it comes to Coburn and Obama, it’s personal.

Coburn is more than willing to take direct aim at Congressional Democrats on health care reform.

For instance, he and Sen. John Barrasso (R-Wyo.), who like Coburn is a physician, have begun taping biweekly television “chat— sessions for the GOP Conference that are highly critical of Democratic plans; he voted against the bill in the Health, Education, Labor and Pensions Committee; and he’s even called anyone who believes in having an “artificial— deadline for completing the reforms “stupid.—

But unlike fellow conservative Sen. Jim DeMint (R-S.C.), who recently urged Republicans to make the health care fight Obama’s “Waterloo— moment, you won’t see Coburn launch such a direct attack against the new Democratic president. Nor, for that matter, is Coburn likely to be a major player in Senate GOP efforts to simply slow-walk the bill to death.

“I’m not a partisan,— Coburn said Tuesday. “This is a problem that has to be solved for our country … but it’s going to require compromise.—

[IMGCAP(1)]But belying the bipartisan platitudes and assertions of wanting to avoid ugly interparty fights is one simple fact: Coburn and Obama are friends.

“I really like him. I have fun with him,— Coburn said. “I like to tease him.—

Coburn doesn’t necessarily come across as an easygoing Senator. He takes his floor fights seriously and regularly gets under the skin of Democratic leaders when he holds up pieces of their agenda.

Even so, even they aren’t surprised that Coburn and Obama are close.

“It’s hard not to like Barack Obama. He’s a friendly, affable guy,— said Senate Majority Whip Dick Durbin (D-Ill.), who served as Obama’s home-state colleague, friend and mentor before Obama won the presidency last fall.

Durbin said the fact that Obama and Coburn came to the Senate in 2005 likely played a key role in laying the groundwork for their friendship, since the then-freshman lawmakers spent a significant amount of time together during their orientations.

Indeed, Democratic and Republican sources close to Coburn and Obama trace the roots of their friendship to that period, noting that while the rookie Senators were hitting it off, so too were their wives: now-first lady Michelle Obama and Carolyn Coburn.

Coburn acknowledged that part of their close connection stems from a shared interest in government reform, as well as the fact that both view elected office as public service.

In addition to public examples of their friendship such as the occasional snapshot of the two hugging or Coburn’s regular social visits to the White House, their relationship is also obvious by the way they treat each other in the political arena.

For instance, several Republicans said that while Coburn was a staunch supporter of Sen. John McCain’s (R-Ariz.) 2008 presidential bid, he refused over the course of the campaign to take direct aim at Obama. And during the campaign, Coburn and his staff worked to ensure both McCain and Obama were co-sponsors of several high-profile government reform measures that he introduced.

These days, while Obama and Coburn are almost always on the opposite side of issues, the duo have been careful to avoid taking unnecessary shots at one another. For instance, Obama and his staff never became engaged in the public fight between Coburn and Senate Majority Leader Harry Reid (D-Nev.) over a public lands measure that Coburn was holding up. And Coburn reportedly sought to keep the partisan rhetoric to a minimum on a report his office produced detailing wasteful projects in the economic recovery bill, one of Obama’s signature initiatives.

But it’s the health care debate where their mutual respect could end up being most evident. As a doctor, Coburn brings a level of weight to the debate that other Members of his Conference may lack in fighting Obama’s plan.

So far, however, Coburn hasn’t taken up the partisan mantle, even as he criticizes the proposal on its merits.

“Coburn’s been working very, very hard to be about substance … and has been very critical of Republicans who have been demagoguing this,— one Senate GOP aide said.

Senate Minority Leader Mitch McConnell (R-Ky.) suggested that Coburn and Obama’s relationship reflects how Senate friendships used to be. He said lawmakers, regardless of how ugly their fights on the floor, used to be able to find a personal common ground.

“There was a time when working on a bipartisan basis to achieve big things for the nation didn’t mean exposing yourself to attack ads by your own colleagues. For years, the Senate was a place where real friendships across party lines were common. These friendships were always good for the Senate, and occasionally they paid major dividends for the whole country,— McConnell said.

Similarly, Durbin noted that over the years he has developed friendships with a handful of lawmakers who use the Senate gym early in the morning, such as Sen. Orrin Hatch (R-Utah). Although a Hatch-Durbin friendship may appear unconventional, Durbin said it is a natural result of their off-work interactions.

“I’m in the early morning shift at the Senate gym. I get there around 6, 6:30, and Orrin Hatch is already there. He’s been there since 5:30,— Durbin said, arguing that having a personal relationship has made it possible for the two to work together in the Senate. “That kind of experience outside the chamber has created the opportunity for dialogue. … I think we need more of that,— Durbin said.

Likewise, Coburn lamented the loss of such relationships, arguing that it has made the chamber a far more partisan place. “There’s a lot of partisan angst. There used to be great opportunities for families to do things together. As things have become more partisan, they tend to have become more personal,— Coburn said.