WASHINGTON (AP) – Donald Trump calls them a “crooked business” and Bernie Sanders says they’re “corrupt” organizations “buying elections.”

But that barrage of insults hasn’t stopped the political groups known as super PACs and their donors from showing the two presidential candidates some love.

A super PAC allied with a union that endorsed Sanders over Democratic front-runner Hillary Clinton in August has spent more than $600,000 on pro-Sanders digital and print ads.

The union’s executive director says the super PAC is assisting Sanders’ bid because “we’ve never seen a better messenger” for causes important to the union’s members.

Sanders and his aides defend the group as “good” big money, drawing a contrast with the wealthy corporate donors he frequently vilifies on the campaign trail.