Requiem æternam dona eis, Domine; In memoria æterna erit justus, ab auditione mala non timebit.
If you can't rely on something at the precise moment that you need it the most, because that thing that you need to rely on is only reliable when the circumstances suit it, then get rid of it.
If the GOP realizes that "purists" will only supprt the GOP when the Party's candidates meet their test, then it may be best to not count on them at all.
Beauseant!