Well, I can't speak for conservatives, but there is wide spread belief among the under 30 crowd that the Republicans are hypocrites. That they hate/dislike gays, but get caught having clandestine gay affairs. That they push the war on drugs, but use drugs themselves. That they preach small government or responsibility, but push through agencies like DHS. That they gripe about welfare, but love corporate welfare.
All of these perceptions range from likely true to very true. Whether they are true or not is actually largely immaterial. People believe it, and perception defines reality. True, the Dems generally get caught doing the same thing, but they rarely claim to the contrary. So it's a question of being stabbed in the front or in the back. People like being stabbed in the front. It's a touch more honest.
I don't like wading into discussions about religion because they invariably get locked.
That said, is it better to aspire to be a good Christian (or Jew, or Buddhist or Hindu or Muslim) and falter than to not try at all? Yes, there are devout Christians who do all of the things that you say. If they're true to their religious beliefs, they'll try to redeem themselves and ask for forgiveness. By stressing their religion, they connect with a large group of voters, but they also set themselves up for public humiliation, as their every step will be scrutinized.
It's much easier to be a Bill Clinton and be an amoral lech during the week, then walk into church on Sunday dodging lightening bolts.