Regarding that Gallup Poll J.P. Green cited just below, The Fix’s Chris Cillizza adds some perspective on it worth noting:

That more than one in four Republicans think their own side is too inflexible speaks not only to the divide between the conservative and establishment wings of the party — nothing shocking there — but also, and this is somewhat new, to the size of the group who thinks the GOP is simply too hard line.
The second, and more important data point, is that the second most-mentioned critique of the party — 14 percent named it — by self-identified GOPers is that they “don’t stand up for their positions” and “give in too easily.” And, when asked the things they like about their party, the three most-mentioned traits are “better fiscal management/budget cuts/less debt”, “conservative views” and “favor smaller government.”
Rock, meet hard place.

Cillizza adds that “giving way on the budget and size of government strikes at the party’s raison d’etre. Compromising on those sorts of things — like the party did in the fiscal cliff deal with President Obama in late 2012 — is likely to lose the party more of its adherents than it gains it in converts.”
He speculates that the GOP will make a big deal about their compromising on immigration, “to change the perception that they are allergic to deal-making,” since only 2 percent of Republican respondents in the poll cited it as a problem. Expect much bloviating from the Republicans in the year ahead about such “nothingburger” compromises.