All those far-right supporters are far outnumbered by the nutroots. I promise you one thing....when Paul loses the nomination in a landslide, most of those Paul voters will vote for Hillary Clinton. Some will vote third party like the Libertarians, but most will vote for the Democrats.
Paul supporters are 2:1:1, republican, independent/libertarain/ democrat. or even 3 or 4 to 1 depending on what survey/poll you look at. Most of his supporters are principled republicans, but no other candidate has as much chance of pulling all the other voters, which will be a key help in the general election. Provided we get there of course.. :)