Obama: Pennsylvania's Hard Times Began Under Bill Clinton

  After Mississippi's primary, tells MSNBC that the Keystone State's troubling economic trends got started during the Clinton Administration. Also denies racial component to Clinton's "3 am" ad, and raises fraud concerns about any mail-in re-vote in Florida or Michigan. Earlier, Obama tells CNN Clinton would be on "anybody's short list" for vice president. Plus: Obama to appear in taped interviews on all three network TV shows Wednesday morning.