One of the more intriguing friendships in Washington is the affinity between President Obama and Sen. Tom Coburn (R-Okla.), one of the most conservative members of Congress.

Today on C-SPAN's Washington Journal, Coburn described his friendship with Obama, noting that the two communicate regularly.

"I try to write him about every week or two," Coburn said of Obama. "Write him a note, encourage him. No one has a tougher job than he does."

The two last spoke when Obama called Coburn last week to offer condolences on the passing of his mother.

"We came into the Senate together, and I just have a lot of admiration for him," Coburn said of Obama. "I'm 180 degrees from him on policy on most issues. But I think he's a wonderful man."

The Oklahoma Republican also noted that he is closer with the current president than he was with George W. Bush.

"Oh by far," Coburn said. "I didn't have...a great relationship with President Bush," he explained, adding that the previous White House didn't appreciate Coburn's criticism of Bush's spending.

See video below: