A moderate, eh? So far, that's all the Republican leadership has done: "moderate" the left-wing. And they aren't even doing a good job at that, seeing as how McCain is well-known for frequently and deliberately "crossing the aisle" to whore himself out to the Democrats and betray not only us but the priceless legacy we inherited from the Founders and the generations before us.
The "culture war" you speak of lies not in the halls of Washington's government buildings but in the minds and hearts of the American electorate. Electing the RINO traitor McCain wouldn't have accomplished anything in fighting said war...because he's not even on your side or on my side. McCain is for McCain.