You forgot to mention a very key element.
48% pay no taxes
42% are on some form of Gov’t program.
These folks have a vested interest in the Status Quo - you can expect a VERY large percentage of them to vote, at least once.
Meanwhile, even here on FR - there are a substancial amount of people who are TOO FREAKIN’ LAZY to do their civic duty, and either refuse to vote for Romney (for either his religion, or his various stances), or will do a write in candidate to make some moral point. A vote for a write-in candidate, or a failure to even vote - is a vote for Obama.
In 2008 I wasted my vote. I voted for McCain.