Vermont Sen. Bernie Sanders dismissed 2024 GOP presidential candidate Nikki Haley's proposal for "mandatory mental competency tests" for politicians aged 75 and older.AP Photo/Susan Walsh Bernie Sanders blasted Nikki Haley's idea of an age-based mental competency test for politicians. "There are a lot of 40-year-olds out there who ain't particularly competent," Sanders told CBS News. Insider's Bryan Metzger last week found scant support for such a test while on Capitol Hill. Sen.