The Tea Party wasn't actually born from the Obama resurgence of liberalism -- that's a narrative they like to spin often so that they can envision themselves as freedom fighters reacting dramatically against a rising tide of socialism. Was it a factor? I can't deny that, I mean if Obama came into office and governed with extreme moderation they probably wouldn't exist. I'd say the current brand of Tea Party is largely a reaction to John McCain being chosen as the Republican Nominee for the President in 2008.
Bush and Cheney ran the Republican party into the ground to the point that no one was willing to even consider voting for another neo-conservative, hardline Republican. The party knew that anyone who had a chance of getting elected in 2008 would have to be a moderate with a record of independence in order to eschew anti-Republican sentiment. McCain got the support because he was the only one running who had a chance of winning. Attempts to placate the Republican base with the likes of Sarah Palin somewhat succeeded (especially while McCain doubled back on many issues to try and seem more conservative to the base in contrast to his reputation as a moderate), but when McCain lost the hardliners put all of the blame at his feet in order to avoid accepting the outright truth that the election was a repudiation of neo-conservatism.
From there this myth was born that the reason why Bush and McCain failed and the country turned against conservatives is because they weren't conservative enough. At the same time the public brand of the Republican Party was melting down. There were calls for ideological purity all over the place, which resulted in many moderates turning away from the Republican Party as their base basically ate them alive.
The Tea Party was born on Tax Day in 2009, and they spread like wildfire not because of the prominence of their ideas (which were very loose at the time, only somewhat partisan, but primarily an outcry against the Bailout and taxes), but because of rabid promotion on Fox News and Talk Radio. Tea Parties sprouted throughout the country, and disaffected neocons found a vehicle back into public prominence as they transformed the Tea Party through media mouthpieces like Glenn Beck and Rush Limbaugh. Dick Army, Newt Gingrich, and Sarah Palin all saddled themselves to the movement, and have been readily accepted -- Sarah Palin even spoke at their biggest convention.
If the Republicans had never sent a moderate in as the nominee in 2008, there would've been no backlash against the Republican establishment, and I highly doubt the Tea Party would've gone much of anywhere. It was hijacked and blown up because it was necessary for them to do so, the party's credibility needed a vehicle to rebrand itself, and the Tea Party worked well.
What's especially sad is there could've been a shift away from the hard-right towards Libertarian ideals that would've left social conservatives out in the cold while growing the conservative party into something that the younger crowd could get behind. While I am no Libertarian, I think they have a lot of ideas I can get behind, and I could see myself voting for a moderate Libertarian easily. Unfortunately, social conservatism seems even deeper embedded in conservative politics than the corresponding governmental and economic principles which actually represent "freedom."
Neither the Republican Party or the Tea Party went Libertarian, the only real difference between them now is that the Republican Party is more pro-business.