We knew this was coming from the second Chief Justice John Roberts botched the oath of office during President Obama's inauguration. This will, no doubt, be just one of the many right wing talking points for weeks, months, if not years to come. (h/t TPM for the video)
Wallace: ..."I have to say I'm not sure Barack Obama really is the President of the United States because the oath of office is set in the Constitution and I wasn't at all convinced that even after he tried to amend it that John Roberts ever got it out straight and that Barack Obama ever said the prescribed words. I suspect that everybody is going to forgive him and allow him to take over as president, but I'm not sure he actually said what's in the Constitution, there."