But you still haven’t tackled the key question: Why would a person, once in office, compromise his conservative principles (or “principles” if you prefer) for the sake of political expediency?
He wouldn’t, if conservative ideas were widely understood by the populace as the best ideas for the country.
I think I did answer the question, just not very eloquently. Rather than work through the Republican party, conservatives need to devote their efforts to support and build grass-roots organizations, which influence and educate public opinion, thus pulling the party to the right along with the populace.