The only Baseball Hall of Fame player to have served in Congress, Mr. Bunning was elected to Cooperstown by the Veterans Committee in 1996.

After serving as minority leader in the Kentucky State Senate, Mr. Bunning was elected to the United States House of Representatives in 1986. He served six terms in the House and then was elected to the Senate in 1998 and re-elected in 2004. He spoke out against spending and taxes and showed a contrarian streak in the Senate while receiving national attention for some strange remarks.

While running for a second Senate term, Mr. Bunning said that his Democratic opponent, Daniel Mongiardo, resembled one of Saddam Hussein’s sons. Mr. Bunning also said he and his wife had been roughed up by supporters of Dr. Mongiardo at a political event, telling of “little green doctors pounding on my back.”

Although President George W. Bush easily carried Kentucky in the 2004 presidential election, Mr. Bunning barely survived the Democratic challenge to his seat.

While discussing the need for conservative judges at a dinner in Kentucky in February 2009, Mr. Bunning noted that Justice Ruth Bader Ginsburg, a member of the Supreme Court’s liberal wing, had undergone surgery for pancreatic cancer a few weeks earlier. “Even though she was operated on, usually, nine months is the longest that anybody would live” with the disease, he said.

He apologized for his remarks about Dr. Mongiardo and Justice Ginsburg.

A critic of Federal Reserve Board policies, Mr. Bunning was the only member of the Senate to vote against the confirmation of Ben S. Bernanke as chairman of the Fed in 2006.