Most Ron Paul cultists never had any intentional of voting for Romney. These are not real Republicans. If they stayed home they did us a favor as most probably would have voted for Obama.
From the voting data I have seen in NH your hypothesis is incorrect. They came out to vote, and often voted split ticket between Libertarian and Republican candidates. But their votes were swamped by Democratic votes from college towns and an army of people dependent on government who the Obama campaign found, misled into believing that the Republicans would harm their interests if elected, and then brought to the polls to vote.