In straight-up primaries, Ron Paul did fairly poorly. In conventions and caucuses where his supporters could show up en masse and dominate the proceedings he tended to do better. For example, he came in fourth (~11% of the vote) in the Minnesota primary when all Republicans had to do was show up and vote. When it came time for the caucuses and conventions, his supporters showed up for multi-hour parliamentary stand-offs that resulted in him winning 91% of the delegates. There was plenty of bitterness all around after that.