I think you see abortion, RKBA/gun control, and now gay marriage played up so hard because they are realistically the only issues in play.
Everything else, you can rely on both parties to pander to the lobbyists hard and at great expense to the voting public.
I don't think there has ever been more than 30% of the public who agrees with what Mr Cain put out as his stance on abortion. His position is popular with GOP primary voters, but with hardly anyone else.
Likewise, I think the percentage of voters who are against private firearms ownership is very small.
Even gay rights/gay marriage isn't as controversial as it used to be.
Now, I do think that larger percentage of people have in-between points of view, that there should be limitations on guns or abortions or on gay rights, but I think the extremes are strictly for the fringes.
AND, I think GOP candidates who embrace the fringes too much to get primary votes are only going to make Mr Obama look Statesman-like by contrast. They run the risk of making Obama seem like the safer choice.
Gramps
I think the real question here is whether these GOP hopefuls are just pandering to those who vote in primaries, or whether they really want to outlaw abortion absolutely.
I am guessing that roughly 70% of Americans would disagree with a total ban on abortion with no exceptions, so it is important to know how serious these guys, like Cain, are about this topic.
How are women supposed to vote for candidates with this kind of platform? I can imagine that some women who still think Obama is a secret Muslim who was born in Kenya might vote for him next year rather than go with an abortion absolutist candidate.