Politico: Obama will have no mandate because he will lose white men!

[Lincoln Republican]

First of all, he said this would not be a broad mandate, he did not say he would have no mandate, as your title states.

That being said, simply by virtue of winning the electoral college vote, a Presidential candidate would have a mandate.

[Lincoln Republican]

However you wish to define mandate, the winner has all the powers of the Presidency, whether he wins very narrowly, or by a massive margin.