Well, the GOP didn't really create the Tea Party, they just commandeered it when it became useful to them. The "Tea Party" as we know it today has its roots in various factions of libertarianism that, at the time they were founded, wouldn't have anything to do with the mainstream GOP. But, just like their godfather Ron Paul, they soon found it was convenient to partner with the GOP in the same way a tapeworm partners with its host organism. The GOP gets their astroturf-y populist group that people can feel good about voting for, and the tea partiers get millions of dollars for negative ads without having to personally whore themselves out to big business (or in some cases, in addition to whoring themselves out to big business.)

This has brought the tea partiers a good measure of electoral success despite the fact that many of their views would prevent them from winning a primary election in most states, much less a general. Of course, now that they're in, I reckon the old guard Republicans will be enforcing some party discipline, meaning that any of them that still thinks they'll be cutting Medicare or Social Security will quickly find themselves eating lunch alone and trying to win elections without the giant piles of corporate cash. Either that, or a civil war will break out, but the tea partiers are small enough in number that I think any insurrection will be quashed pretty quickly. I'm curious to see what happens to these bombastic tea partiers once they get in. My prediction is that most of them will morph into garden-variety Republicans, a few will stir the pot a bit, but ultimately, there will still be near-100% ideological purity within the GOP caucus and almost no split votes on any bills of substance.