Thank goodness there are too few of those "purists" to make even a small ripple. The vast majority of common sense conservative voters know there is no perfect candidate. You vote for the most conservative candidate who is running, period.
Last time the estimate was four million - obviously not all FRers - who sat it out, costing, by some accounts, the election. If Trump folds, his Trumpeters will likely follow suit - judging by their general lack of maturity, and pushy, picky natures.