2. The chief cause of misunderstanding is the issue of trust. The White House thought that that if they had all sorts of conservative mechanisms in the bill that conservatives would be placated. What they didn't understand is that the anti-"amnesty" wing of the Republican party simply doesn't believe any of these enforcement measures will implemented until they in fact are implemented. "Trust but verify" has simply become "verify." And until there is real enforcement — both in terms of current law and new laws — the base simply doesn't care about any other bells and whistles. "Been there done that" is the de facto official policy of the base when it comes to promises of enforcement, i.e. "No more promises, just enforcement. Then we'll talk" (This basic reality is why I came out in favor of a wall on the border).
If we actually believed that Bush could do what he said he says he wants to do... well that would be quite a world, wouldn't it?