Maybe this is obvious: When voters are continually betrayed by those they put in office, they often resort to unapproved methods. I remember when David Duke was almost elected to the Senate from Louisiana in 1990. He got 43% of the vote! Were that many voters racists? I doubt it. Why would they vote for him, then? Well, take one of Duke’s issues, welfare. For decades, conservative voters had supported politicians who promised to cut welfare, end welfare, support workfare instead of welfare–only to see welfare spread to cover more of the population. Voters didn’t understand there were children on welfare! Recipients had “barriers to employment”! You couldn’t expect them to work! Etc.
Louisiana voters may have figured, “Everyone we elect sells out on this issue. But this guy Duke’s a f**king racist maniac! At least he won’t sell out.” Wackiness and bigotry became markers for “he means business.”
A similar, though less extreme, dynamic is clearly working in favor of Donald Trump.** Republican voters have sent lots of politicians to Washington who promise to get tough on border control and wind up supporting amnesty within about 35 minutes of their arrival. Marco Rubio, come on down! (Also Renee Ellmers and, um, Eric Cantor.) It’s all too realistic to expect that Scott Walker and even Ted Cruz will join these Election Day converts to comprehensivism, should either win national office. But this Trump guy — he’s out of control! He means business. He might actually build the danged fence.
This is also why Trump will likely be punished if he backpedals and apologizes for his wild overstatements disparaging Mexican illegals. It would have been easy for Trump to say he spoke imprecisely — ‘the vast majority of Mexican illegal immigrants are good people, but we’re getting a lot of bad people too, etc.’ [which I believe to be the truth***]. Talk more about the effect even law-abiding undocumented workers have on wages. He hasn’t done that. He knows voters regard his behavior as a sort of trial run for how fast he’d cave in office.
** — Chris Matthews made this point today, before (absurdly) endorsing the Senate Gang of 8 amnesty bill as a way to placate “those angry about illegal immigration.”
*** — I’ve just finished Ann Coulter’s anti-immigration polemic, Adios America!, which may have influenced Trump. Coulter talks a lot about immigrant rapists, but she doesn’t say Mexico is sending us the dregs of its society, nor does she suggest that most Mexican illegal immigrants are criminal types. She says they come from a peasant culture, and peasant cultures are not known for, say, their progressive treatment of women.