Coburn reaffirms term-limit pledge, won't run in 2016

Coburn is a member of the Senate "Gang of Six" that ultimately proposed $4 trillion in combined spending cuts and new revenue, and on Monday reiterated his support for some higher taxes on the wealthy to help the government dig its way out of debt. This position put him at odds with most House Republicans earlier in the year, although Democrats are expected to once again press for new taxes as part of the effort to trim the deficit by another $1.5 trillion.

The senator has clashed with the GOP leadership on previous occasions and earned the nickname "Dr. No" for repeatedly blocking legislation. And despite his strong conservative leanings, he's a close friend of President Obama's.

In the meantime, Coburn criticized the debt-ceiling deal for failing to make real spending cuts.

"The budget deal didn't cut anything," he said. "Discretionary spending will increase $832 billion in 10 years. They didn't eliminate anything, it's a fraud."