On immigration, it seems that the RNC poll, as well as the recent USA Today article, shows that the hard-liners are not in the majority, but instead a minority. The USA Today article shows four groups: Hard-liners, unconcerned, the ambivalent, and the welcoming.
Only among the hard-liners - and then, only 70% of them - want the fence built. The fence cannot get a majority in any of the other groups discussed.
Deep down, the hard-liners know they are a minority, but there is constant denial of this. They cloak their arguments in "rule of law" - but they are so caught up in enforcing the law that they do not stop to ask if the law they are demanding strict enforcement of is a good law.
And now, facing the real possibility of defeat, they have ratcheted up the rhetoric. On some places, there are claims that those who support the President's approach are Quislings, or they support the gradual overthrow of America. Others call for impeachment. Others make claims that the law is being subverted. They even threaten to stay home if they do not get their way. There is an increasing shrillness from their side of the discussion - the same sort of shrillness seen from the anti-war movement that knows its desires for American defeat are not shared by the bulk of the American people.
If this isn't scorched-earth tactics, I don't know what is. The sore-loser aspect of the scorched-earth approach of Tancredo and Sensenbrenner is bad enough, but many of these people are going to leave a lot of legal immigrants with the impression that conservatives (who tend to be Republicans) never wanted them to come here in the first place, and who will vote accordingly. The hard-liners, unable to get their bill, have managed to poison the well for the near future.
It's a form of blackmail - and it's reprehensible. The Republicans need to break this cycle in order to focus on the war on terror, entitlement reform, and other issues that are far more pressing than immigration.