Former Vice President Joe Biden made a high-profile gaffe at the third Democrat primary debate on Thursday, mistakenly referring to himself with a title he never held.

“I’ve been involved from the beginning, as a young congressman — councilman, I introduced legislation to try to keep them from putting a sewer plan in a poor neighborhood,” Biden said while delivering a rambling introduction to his position on criminal justice issues.

The statement was perplexing, as Biden never served in the U.S. House of Representatives, whose members generally refer to themselves as “congressmen” or “congresswomen.” In fact, prior to ascending to the vice presidency in 2009, Biden had spent his entire congressional career in the U.S. Senate, whose members generally are not referred to as “congressmen.”

The gaffe is similar to those that Biden has repeatedly made on the campaign trail in recent months. Last week, the candidate appeared to forget his former running mate, Barack Obama, was America’s “last president” during a swing through New Hampshire.

Such gaffes and questionable statements have led many on the left, including Biden’s own allies, to question if the former vice president is fit to run and hold elective office.