Donald Trump explains to David Letterman his $5 million charitable challenge for President Obama to release his college records and his passport application:

And after the jump, watch Stephen Colbert’s report on Trump’s “October surprise” offer, with Colbert’s $1 million counter-offer to Trump. Plus a clip of Barbara Walters on The View, telling her friend Trump “You’re making a fool of yourself.”

Related Video: Obama Mocks Trump On Leno