Would Alison have served herself better to respond something like this?
"Yes I did vote for Barack Obama in 2012, like nearly half a million Kentuckians did. Do most Kentuckians agree with that vote? No. But in 1992, Senator McConnell voted for George Bush and most Kentuckians did not. In 1996, Senator McConnell voted for Bob Dole and most Kentuckians did not. So instead of talking about one vote I made as a private citizen nearly two years ago, let's talk about the votes this debate should be about - the votes I intend to make as a United States Senator and the votes Mitch McConnell has made in the Senate that have been wrong for Kentucky and wrong for America."
That's good, you should email that to the campaign. :-P