Sen. Elizabeth Warren had a hard time defending her support of former President Biden's mental fitness when pressed in a recent interview. Why it matters: It's the latest example that Democratic leaders had doubts about Biden before he stepped aside last summer.

Warren was pressed about her past comments in an interview on the “Talk Easy with Sam Fragoso” podcast, where the host asked the Democratic senator if she had any “regret” over defending Biden’s mental ability. “I said what I believed to be true,” Warren said in the interview released Sunday.