Coulter is actually just parroting what many others have said.
Obama won in 2012 because his campaign went hard left, identified people who agreed with him but who traditionally didn’t vote, and turned them out to vote.
While Romney went the route of trying to convince undecided Moderates and leaners to vote for him.
Results speak for themselves. There’s a near graphical representation from the PJ Media Catalist article that I’ve posted in the past showing this.
Obama is merely a symptom of the disease.
Romney won independents 50% to 45%. Romney won the white women vote 56% to 42%. He won white men 62% to 35%. Romney won the married vote (all races) 56% to 42%.