I don't care what you believe or support. If you don't think that obama flipping the SCOTUS to a liberal majority will be a huge problem for gun rights than that's your problem. I am not willing to risk it. McDonald and Heller were decided by 1 vote, and there are tons of 2A cases working their way through the courts right now. If you want a liberal majoiry making the decision on those cases then vote for someone other than Romney. I will not throw away my vote this year, control of the SCOTUS is too important.
I normally vote libertarian, but obama has already appointed tons of anti-gun judges in the lower courts these last 4 years, give him another 4 and you will lose you 2A rights via judicial activism.
ETA- this is what Justice Breyer said in his dissent- "In sum, the Framers did not write the Second Amendment in order to protect a private right of armed self defense. There has been, and is, no consensus that the right is, or was, 'fundamental.'
Does that sound like the type of person you want deciding your 2A cases? Because that is exactly the type of person obama will appoint if elected. Breyer was appointed by Clinton, who was elected because people decided to split the vote between Perot and Bush Sr., just as you are suggesting this time. It has happened before, and it will happen again if 2A supporters divide themselves this election.