Clinton is better positioned to beat Obama in swing states according to everyone who has any logic and almost every single poll out there - http://www.reuters.com/article/politicsNews/idUSN0234370120080402
To me, the logic for supporting Clinton over Obama is simple.
1) Clinton can beat McCain in "must win" swing states like Florida, Penn and Ohio
2) Obama has won a ton of red states (which will go to McCain) and has yet to get a decisive victory in ANY swing state, major blue state or purple state.
3) Therefore, due to issues of race, lack of faith in his experience or the need to have someone a little more long in the tooth on the national stage - whatever the individual reason -- if Obama gets the nomination the Democrats will LOSE to McCain. Its SO obvious.
1 plus 2 equals 3 -- and in this case 3 is four more years of a Republican.
I truly hope Clinton trounces Barack in Penn, wins Indiana and North Carolina and then makes a stronger argument to count Florida and Michigan. Honesely, the threat isn't the Clinton's stealing the election - the threat is blind idealism handing the election to the Republicans. Common-frakkin' sense - middle America is NOT ready for Barack Obama.