I would have doubts that they are that stupid. If it does occur....probably half of the people who would have voted in the primary season....will just stay home or cross the aisle to vote in the Democrat primary (maybe even for Hillary to make things interesting).
Long-term damage would be a total split in the party and marginal ways for any Republican to win for any major office (President, Senator, House Member or Governor) for at least a decade.
It’s the national party’s own fault that they became so entangled in special interest groups and lobbyists....become the Fairfax Party instead of the Republican Party and just representing a 30 by 30 mile area of Virginia.
They didn’t even represent Virginia well judging by Eric Cantor’s booting.