Thetea party has lost some momentum in Congress. The government shutdown was a reminder that confrontation can backfire and that Americans actually like a certain level of government service.
Still, the tea party faction retains considerable influence. Is it responsible for GOP problems in devising a positive agenda? Not exclusively --tea partiers are only part of the story. Different issues involve different constituencies and different ideological perspectives within the party.
With unemployment insurance, the tea party faction makes common cause with deficit hawks such as Senator Mark Kirk (R-IL).
With immigration reform, there is widespread opposition within the GOP, and not just among self-identified tea party folks. The GOP grassroots grew skeptical of liberalized immigration laws long before the tea party started in 2009. A big part of the story was the perceived failure of Simpson-Mazzoli.
ENDA faces opposition from the religious right, which is separate and distinct from the tea party. See:
As for the “Paycheck Fairness” bill, opposition comes from all wings of the party: business interests, traditional conservatives, tea party folks, the religious right. With business, obviously, self-interest is involved, but most Republicans just think that it’s very bad policy. Indeed, opposition to such ideas goes back decades: Reagan economic adviser William Niskanen called "comparable worth" -- Paycheck Fairness 1.0 -- "truly crazy."