"It's so corrupt, so dirty, you wonder if you want to apply your life's work" to it, Kirk told the Chicago Tribune's editorial board. "I'm more of a federal guy."

Blagojevich faces impeachment and has been indicted on federal corruption charges. It is possible Illinois would hold a special election next year to select a new governor should Blagojevich be removed from office.

Kirk, who represents Chicago's North Shore area, is fresh from a tough election battle for a fifth term in Congress. He told the Tribune he had considered running for Barack Obama's U.S. Senate seat had a special election been called.