Grance Franke-Ruta has a piece up at the Atlantic trying to explain why House Republicans keep voting to repeal Obamacare in vain. As she sees it, it's because of an "ideological fixation" or the 19th Century psychological concept of an Idées fixes as seen in literary figures like Captain Ahab. It's one of those interesting arguments that makes for good filler on a website but personally I think these types of psychological explanations for problems in the modern GOP are less than helpful.
The main reason that Republican politicians do things like vote over and over again to repeal Obamacare while offering no counter proposal of their own is because of structural, not psychological reasons. Over the last few decades the conservative movement has set up a huge infrastructure of money making ventures that conservatives figures and Republican politicans can tap into to make a lot of money. Like books, TV jobs and cushy think tank positions that are yours for the taking as long as you tote the conservative hard line. Boston based journalist David Bernstein has argued that a lot conservative movement works not as an ideological movement, but a private industry that creates conservative "products" to be sold to a vast market of older, white suburbanites with large amounts of disposable income. Think of Glenn Beck, who talks about the oncoming economic collapse we are facing because of things like deficit spending and then goes on TV and radio as a paid spokesman to hawk over priced gold coins as a sure fire way to protect your investments during the future economic collapse. Rick Perlstein once wrote a great history of the creation of this market in The Baffler.
The result is that perverse incentives are set up inside the GOP that leads intelligent, rational people to hawk bizarre conspiracy theories or push for "investigations" of made up scandals because there is a big pot of gold at the end of their career rainbow. Meanwhile, if you criticize the conservative movement for being unrealistic, bad for the country or not very good at stopping Obama, you get fired from your think tank job for writing things like this.
There are a number of other structural problems with the Republican Party right now, for example the massive policy gap that's opened between them and the Democrats. As well as an aversion to normal compromise and negotiation that we've seen in recent years. Indeed, a functioning political party would probably accept it's can't overturn or "defund" a law when it only controls one half of one third of the government. But the reason for this dysfunction isn't physiological manias, it's structural. Which is why the GOP won't fix itself just by getting rid of a few blow hards like Michele Bachmann.