Most partisan political debates are at least somewhat dishonest, with both sides concealing somewhat unsavory motives behind grand, idealistic rhetoric. The current immigration debate, however, may be setting new standards for bipartisan hypocrisy.
Supporters of the bill--primarily Democrats--claim to be saving millions of poor, oppressed illegal immigrants by granting them legal status (so-called "amnesty"). Of course, amnesty will do nothing of the sort: if the newly-legalized immigrants take advantage of their new status to escape their ill-paid, backbreaking labor, then employers will simply shun them in favor of fresh illegal arrivals, creating not one, but two underclasses--unemployed legal immigrants and their illegal replacements.
That's supposedly why Republicans want any amnesty tied to vigorous "enforcement"--meaning sealing of the US-Mexican border. The premise, presumably, is that once the amnesty is declared, the millions of new illegal immigrants who will rush to take their place must be stopped at the border. In practice, though, border interdiction can at best slow, not halt, the flow of illegal immigrants. (Think of how effective it is at interdicting drug trafficking, for instance.) Eventually, the supply of illegals will have been fully replenished, and "enforcement" will have come to naught.
There is, mind you, a highly effective way of massively reducing the number of illegal immigrants, with or without amnesty. It's no mystery--it's known as "employer sanctions", and it was supposed to be a part of the 1986 amnesty, but was never seriously implemented. The principle is simple: illegal immigrants come to the US because even the awful under-the-table jobs available to illegals are better than their prospects back home. However, if employers are harshly penalized for employing illegal immigrants, then the illegals will no longer be in demand, and therefore no longer have an incentive to come--or even to stay, if they've already arrived by now.
Employer sanctions would require a fair bit of work, of course--establishing a database of citizens, an effective identification system, and an inspection system to catch scofflaw employers. But given that these things have been built for cars and guns, it shouldn't be impossible to do the same for people. And the system needn't be perfect, because employers--unlike, say, gun owners--tend to be affluent and respected enough to want to avoid the risks associated with breaking the law.
One could raise some legitimate, though minor, concerns about this regime, such as whether the database jeopardizes personal privacy, or whether legal job applicants of the wrong ethnicities would come under undue suspicion of being illegals masquerading as legal. Employer sanctions also face opposition from politicians who see partisan benefit in the perpetuation of the illegal immigration problem: Democrats who see the illegals as potential Democratic-voting future citizens, and Republicans who see their employers as potential Republican-donating business tycoons.
But the real reason why serious employer sanctions aren't part of the current immigration bill--and barely figure in the debate at all--is that the perpetuation of the illegal immigration problem benefits many more Americans than just the aforementioned political operatives. In fact, virtually every American pays lower prices for goods and services provided by a host of industries whose millions of illegal workers would have to be replaced by legal workers--at a much higher cost--if employer sanctions were put into place. Indeed, nobody knows where those legal workers might come from, how much they'd cost, or whether customers would be willing to pay the bill. In other words, the exploitation of millions of Mexican workers with no alternative is a massive and crucial portion of the American consumer economy, one that few Americans want to give up.
Of course even fewer Americans want to admit that they depend on the illegal worker system for their low-priced goods and (especially) services. They'd rather engage in pointless arguments about amnesty and border control instead.