Well, hold on a second. Do you believe that there are positions that people can't seriously and thoughtfully take? If so, is there any particular reason to think that a political party can't adopt a bunch of them? The Republican party is crazy. This sort of thing happens. There have been many political parties throughout history that were crazy or downright evil. Some of them were even able to exercise a great deal of power.
There are a few varieties of conservatism out there. Most people who would identify simply as "conservative" are radical utopians with authoritarian tendencies. I'm not using those words as pejoratives - they want to enact major changes in policy in order to make society as they think it ought to be in most every particular and what they think society ought to be usually involves people knowing their place. Their utopia always sounds like a pretty nasty place and I have yet to meet one who has actually tried to think through exactly how we're going to get from A to B. Many look forward to some sort of cataclysm that will shake the country from its stupor and put it back on a righteous path. This kind of conservatism is crazy.
There are "social conservatives" who are mostly concerned with Christianity, abortion, and homosexuality. This can be serious to the extent that their religious beliefs deserve to be taken seriously, I guess. They still clearly have persecution complexes, but they're often open about just wanting to force Christianity on everybody else. Clearly evil, but maybe not crazy.
There are apathetic "fiscal conservatives" who don't really care much about politics and aren't very informed. They're vaguely concerned that we spend too much money. Not serious. Some people care more but are clearly suffering from textbook false consciousness. Serious but sad.
There are people pushing this sort of "fiscal conservatism" because they seriously and thoughtfully conclude "fuck you; got mine". Evil.
I would say that's a bit unfair. Is the republican party AS A WHOLE crazy? probably not. They comprise about 30% of the country or so, they can't ALL be lunatics. Remember that there are a significant number of governors, state representatives, etc that aren't completely terrible. REPUBLICAN LEADERSHIP at the moment is off the wall though for a lot of reasons, not the least of which is that a vocal fringe is making it very hard to get things done without catering to them. Our primary system is going a long way towards making this possible. The vast majority DO NOT VOTE in primaries, making it very easy for radicals and fringe politicians to hijack the process. Many moderates are taking extreme positions out of fear of getting "primaried." this goes back before the tea party, "club for growth' has been doing this for a decade or more. I actually don't think Boehner is THAT bad of a person- not next to people like Santorum, Bachmann, Gingrich, Cruz, etc. He's just bad at his job and in a terrible position. Sort of like Bush II, in a way.
Some republicans are single issue voters- and a lot of times that issue is abortion. These are highly religious people that just can't get past the view that abortion is simply legalized murder, all life is sacred, and every other issue is secondary to that. Do I agree? hell no, that position is terribly naive. But the republican party leadership gets a lot of mileage out of exploiting these people. "we will make abortion illegal and save babies, isn't that what's REALLY important?"
Many voters simply vote the way their parents and friends do, and don't have the critical thinking skills or resources to dissect arguments that "sound right" or appeal on an emotional level, but don't actually have any weight or substance. "reduce the deficit!!" sounds great. sounds sensible. But ask "why?" and it sort of falls apart. Most assume government debt is a lot like household debt, and it simply isn't- but most people- even those with degrees are nowhere NEAR well equipped enough to start discussing monetary policy in an informed way. Hell, most of this board isn't either.
Misinformation is another tool. Many are simply misinformed, thinking Obamacare does a lot of things that it really doesn't, and the Party leadership uses fear as well as wholly owned media outlets to reinforce their talking points, knowing they'll never be called on them.