Didn't Ronald Reagan say that conservatives shouldn't criticize each other, but should keep the criticisms to the Democrats? And wasn't that what got him elected President? I'm sure someone will find the quote exactly somewhere, but I have always thought it was brilliant.
It's Reagan's 11th commandment.
Thou shall not speak ill of another Republican, (or conservative).
Reagan also said, if you agree with someone 80% of the time, you're both on the same side of most issues. Reagan believed in fighting Democrats and keeping peace for the most part, within the Republican Party.