Traditional marriage lost by more than half a million votes. You can’t have that much voter fraud without it being very easy to see. The leftists were just more motivated to vote than the conservatives.
The Left won on gay marriage by successfully selling themselves as modern-day abolitionists fighting for a cause that is just and right while successfully portraying the opposition as Fred Phelps with his "GOD HATES FAGS" signs. There was no middle, no debate. You were either a kind, caring, compassionate person or you were Fred Phelps.
Nobody wanted to be seen standing next to Fred Phelps.