The actor and director joined Twitter and launched a series of posts against him.
In The Know
A contestant from "The Bachelorette” wants to be Trump's VP.
The resolution passed by unanimous consent.
But he doesn't think Trump is a racist.
Obama wrapped up his performance with a double mic drop.
The man behind the site worried it would be viewed as a parody.
"The View" host used a risqué joke to urge Sanders to end his campaign.
The two made appearances on NBC's "The Tonight Show."
Obama also said Hillary Clinton was "whip-smart."