It would be a very odd party mainstream to produce a lower figure.
And honestly I'm not entirely sure we should really consider Paul's ideology, or a large part of his base, as outside the party's mainstream anymore. (Though the man himself probably still should be.)
True, but there is a certain narrative that the GOP is locked into a battle between "the establishment" and "the base", when it is probably more accurate to say that different parts of the GOP establishment are/were fighting over the direction of the party.
And yeah, I suppose you're right about Paul.