The answer is that it's not acceptable for either party to do it, which is why I will not vote for Romney or Santorum. The double standard is because GOPbots pretend they're better than the Dems when it comes to freedom and American values, but can't walk the walk when it comes down to it. Instead of attacking the 2nd Amendment, they prefer attacking the 4th, 6th & 10th primarily.
And don't forget the 7th Amendment.