You are so dead wrong it is amazing! Once you've demonstrated that you will vote for a less-than-acceptable Republican because you "fear" the Democrat may be elected instead, what sway do you pretend you can hold over that person? The correct answer, for anyone who knows the first thing about politics, is NONE. They know that you will vote for them so long as they have the magic "R" behind their name, and you have forfeited any measure of authority because you are unwilling to vote them out of office.
So much for "make them pure". Sounds good on paper, but it doesn't work in the real world. What happens is that more and more centrist Republicans get elected.
BTW, I wasn't talking about making the specific candidates "more pure" once they got in there. My point is, let's get the conservatives in there, RINO or not, and once the liberals are out of power and we have the incumbency, than we can worry about replacing the RINO's with more conservative candidates. But until we get a foothold, we ain't getting s**t.
The political facts of the last 45 years do not bear you out.