By not voting, they voted for ... no one. Zero. So the total vote count, lacking those 4 million votes of conservatives, made Obama's overall percentage of support falsely inflated and represented.
NOT voting is dumb, to me. It's wrong, too, because the franchise was paid for in blood. Men died so we could vote; to blow it off because we don't like the way Democrats and Republicans do things, is wrong.
But there is no voting "against." There is no "voting 'for' when you don't vote,'" not even effectively. It's like a light switch, on or off. You only get to vote FOR.
Had enough "sick of it" Americans who stayed home, gone to the polls and voted for a sure-loser Don Quixote and split the total vote into a plurality, it would have actually HELPED the right because then, Obama's overall percentage of support would be a minority of Americans. On real paper, in real numbers. And that would make him weaker, the way it hurt Clinton both times it happened to him. Obama would face the world with everyone knowing that two in three Americans rejected him at the ballot box.
Like you, JSteff, I get frustrated when I hear "conservatives" say they're just not going to vote, to hell with it. That is surrender.