Social Conservative Republicans are Conservatives. What you call Politically "conservative" Republicans are for the most part people in love with the evil of abortion and often with the evil of homosexuality. They are no more conservative in the current sense than a George McGovern, a Slick Willy, a Hillary, an AlGore, a John Kerry. Budget balancing by raising taxes for "the arts" and for gummint education is NOT conservatism. Nancy Landon Kassebaum Baker is NOT a conservative and neither are what you erroneously describe as "politically conservative Republicans" (i.e. the pro-abort buffalo wing of the GOP) any kind of conservative. Instead they are anachronisms and the sooner the GOP is rid of the Planned Barrenhood types the better.
The difference between us is that you would back Hillary Clinton if you believe beyond any doubt that she was anti-abortion and anti-homosexual. She could do anything else but so long as she was with you in those two areas you would be behind her through thick or thin, do or die. That's not conservatism.