If rain is pouring and you don't want to get wet, you have a few choices. You can stay inside. You can put on a raincoat, grab an umbrella and brave the torrent. Or you can step outside and demand that it stop.
This last option has obvious advantages. It doesn't interfere with your daily routine, and it doesn't require rain gear. The only flaw is that it doesn't work.
Congress faces a similar choice when it comes to immigration laws. A tentative consensus has formed around a package of changes that would let many people living here illegally stay and eventually gain citizenship. But some conservatives are opposed to what they deride as "amnesty." They insist instead on going on an enforcement spending spree, while barring undocumented foreigners from any hope of becoming Americans.
Both ideas reside in a dimension far removed from reality. Efforts to secure the border have been radically intensified in recent years without stopping people from sneaking in. Efforts to make life miserable for those who are not supposed to be here have not made them leave.
Conservatives usually recognize the futility of resisting powerful market forces. They know that price controls and minimum wage laws have a way of backfiring. But some of them exhibit a touching faith that with enough diligence, the federal government can seal off the U.S. labor market from the world.
It can't. When a relatively poor country whose jobs pay little shares a long border with a rich one whose jobs pay much better, many of those in Country A will migrate to Country B -- even if it means they must pay large fees to criminal smugglers, risk death in crossing, do dirty and unpleasant work and endure the constant danger of being arrested and evicted.
Today, the government spends nearly 10 times as much on the Border Patrol as it did in 1993. What does Sen. Ted Cruz, R-Texas, propose now? Tripling the number of Border Patrol officers and quadrupling outlays on surveillance gadgets. But if carpet-bombing the Rio Grande with cash hasn't worked so far, it probably isn't going to work in the future.
The trouble is that border agents have to succeed every time a particular migrant tries to cross, but the migrant has to succeed only once. A 2009 study from the Center for Comparative Immigration Studies at the University of California, San Diego found that "of those who are caught, all but a tiny minority eventually get through -- between 92 and 98 percent."