South Dakota Congressman Dusty Johnson said Tuesday that some members of Congress don’t have the mental faculties to physically know where they are when they are casting votes in the U.S. House.

“I serve with dozens of members in the House who are not with it,” he said.

Johnson, a Republican, made the remarks at a luncheon hosted by the Greater Sioux Falls Chamber of Commerce. The comments came in the context of age and workforce. Johnson supports legislation that would ease the mandatory retirement age of airline pilots from 65 to 67, and he said that South Dakota’s requirement that judges retire at 70 is sound policy.

Voters in some House districts don’t realize their representatives suffer from mental degradation because so many districts are not competitive, either safely Republican or Democratic. Those members don’t have to make public appearances or work to get re-elected, and they spend decades serving in Congress.