"Things in politics change, but they change through demand. I give you the opening section of Rick Perlstein’s Before the Storm:
… the American right had been rendered a political footnote–perhaps for good.
The wise men weighed in. Reston of the Times: “He has wrecked his party for a long time to come and is not even likely to control the wreckage.” Rovere of the New Yorker: “The election has finished the Goldwater school of political reaction.” “By every test we have,” declared James McGregor Burns, one of the nation’s most esteemed scholars of the presidency, “this is as surely a liberal epoch as the 19th century was a political one.
The rest, of course, is history. Conservatives won. And they won not despite losses like the Goldwater campaign, but precisely because of them: because they are and have been entirely willing to lose individual elections if it means dragging the fight to the right, and in doing so setting the middle in such a way that even when Democrats win, they lose. Every time some Tea Party candidate defeats an establishment Republican and loses an election, the national media laughs. But the center will have been established, and future Republicans will know that they must move to the right to ward off such primary challenges, and eventually they’ll win, in large measure because terrified Democrats will refuse to make any meaningful attempts to define their party or what it is for. And so when Democrats ride an unprecedented electoral wave, inspired by the most incompetent and corrupt administration in a hundred years, and invest incredible political capital to barely scratch out a legislative win for their health care plan, that health care plan is the one written by Heritage. That’s how conservatives win.
Conservatives do not allow their politicians to say “we can’t push for that, because of Teh Politics.” They make demands, and they enforce those demands through the primary process, and that in turns changes the politics. Democrats preemptively declare defeat on all things, and the Jon Chaits carry their water."