It is the fact that very few "conservatives" are just that, conservative in the Reagan/Goldwater way. A few points off of my pointy head:
1. Republican leadership has abandoned fiscal responsibility in favor of buying votes with the peoples' money EXACTLY like democrats. It is merely a matter of whose vote they are buying, not whether they are buying them
2. Social conservatism hasn't ever been, nor is now a losing issue. It is portrayed that way by the press, but quite the contrary, issues like pro life, while not necessarily a lead item on the platform, DO NOT cost republicans votes. The pro life position, in fact, according to the latest Pew Research polling, is now the majority position. My point is that no one should shy away from sincerely held beliefs on either side. What scares people off is double speech.
3. Strong military defense wins votes, period.
4. Limited government is a no brainer, no nonsense issue. If we can't have a discussion about this with our 5 year olds that even they can understand, then we all need to do some soul searching.
Bottom line, if we had ONE conservative leader as articulate as Daniel Hannan of Great Britan, we'd win huge. Reagan policies are still winning policies.