I realize that the Republican Party sadly has not been the party of fiscal conservatism, but the Tea Party movement has been trying to change that. Their efforts are the main reason why the Republicans have a House majority now. I believe that the Republican Party and the Tea Party movement need each other to thrive. The Republicans need conservative principles and policies, and the Tea Party would have a very rough go as a third party. Eventually, they may have to break free if establishment Republicans continue their grip on the party. I'm disappointed that John Boehner is still House speaker. It should be Paul Ryan.
The Tea Party's all-or-nothing hard line stance is what's hurting the Republican Party. The problem is similar to what the Dems had in the 70s and 80s... the extremism it takes to win the primary winds up hurting the candidate in the general election. To Tea Partiers, moderate Republicans are bigger enemies than Democrats, and they will do anything in their power to flush them out of the party.
The only way the Republican Party will survive is to ditch their draconian social platform. Fiscal conservatism isn't the problem (as much as the conservative echo chamber is framing this as an election of moochers vs. self-reliant Americans). The big problem is with social issues. All this "legitimate rape" stuff absolutely killed Romney with women. Hard-line immigration stances kill the party with hispanics. If the GOP could run a candidate who is not aggressively pro-life, who is not aggressively anti-gay, who is not at all anti-science, and shows some understand of women's issues (hot tip: birth control pills have more uses than just birth control), they might have a chance. But with the current TP/religious right base, that candidate would never win in the primaries.