They know he's not in their pocket. They also know that millions of their members are supporting him. So, instead of accepting the will of their members, they're going to use their dues to try to thwart it.
In the coming months, the AFL-CIO, which has not endorsed a candidate in the primary but has encouraged members to support the Democratic nominee, will launch digital attack ads against Trump and will ramp up its door-knocking campaign. The Service Employees International Union, which has endorsed Clinton, has organized phone banks for her nationwide, including most recently in Pennsylvania in the hope of getting out the vote on behalf of Democrats.
Read the story @ US unions plan attack on Donald Trump in attempt to derail presidential bid