Democrats and liberals actually oppose it. Most Republicans support some sort of reform and it's only the demagogues like Tancredo® that scare off some GOP members.
The fact is, almost no Democrat is credible on the issue of immigration and almost every Republican is, because at the very least Republicans are law-and-order.
And unless the Tancredoites can manage to nominate a challenge candidate who is not -- how should I put this? -- insane, they will look even more fringe than they really are.
We'll see how important it is in those districts. Some of the House hearings are going to be held in them.