Former Democratic presidential candidate Howard Dean has joined the growing list of prominent political figures who believe Donald Trump’s refusal to release his tax returns suggests he’s hiding something major.

Dean, who has endorsed Democratic front-runner Hillary Clinton, wrote Tuesday that there are “problems” with the presumptive Republican presidential nominee’s reluctance to make his tax returns public.

Recommended Stories

Clinton camp: What does Trump have to hide in taxes?

Paul Ryan: Trump needs to ‘overprepare’ for first debate

Reagan official endorses Clinton: ‘I have never voted for a Democrat’