Meghan McCain, whose father apparently ran for some political office at one time, certainly knows how to attract attention. Unfortunately, at least among doctrinaire Republicans, it’s generally of the wrong sort. Her most recent outing was a speech delivered to the Log Cabin Republicans’ 2009 convention. In an occasionally rambling but hopeful address, Ms. McCain drew fire from the punditry for daring to give voice to an ugly truth which many party loyalists would rather not contemplate: if the ideological purists of the GOP — particularly the social conservatives — wish to thin the herd by driving all the RINOs...