Ronald Reagan is often quoted as saying that someone who agrees with you 80 percent of the time is an ally, not an enemy. Which is fine as it goes. But what about Republicans who regularly violate the GOP platform and fall well below the 80 percent threshold?Meanwhile, the late, great conservative William F. Buckley is often quoted as saying conservatives should support the most conservative candidate who can win - meaning that in Democratic-leaning districts, a moderate Republican would be preferable to a liberal Democrat.But what if the moderate Republican is running in a Republican-leaning district? In that case, …