Ultra-conservatives take a hard line. "Round up all the illegals, make them all felons, and prosecute them to the fullest extent of the law!" they say. "Then throw them in jail and, when they get out, deport them. Meanwhile, build a wall so no more can get in."
More moderate Conservatives want to round them up and send them home, and a "guest worker" program that will allow Mexicans (mainly) to enter the country to work during the day and then return to Mexico at night.
The immigration issue turns on three facts:
The US has 20,000 miles of borders a 2,000 mile border with Mexico, a 5,500 mile border with Canada, and 12,400 miles of coastline;
As a group, undocumented immigrants are not in this country to freeload or to terrorize. Most of them already have jobs; they already use our education, healthcare, transportation, law enforcement, and welfare systems, and in many cases they own their own businesses and homes. They already spend money. They may not pay taxes, though.
But even if we could, there would be no place to house them. The prisons are full with a population of 2 million inmates; it would be impossible to increase that population by a factor of nearly seven.
But even if we could, there would be no way to give them speedy trials. All the judges in all the courts in the country could not dispose of 12 million cases.
But even if they could, there is no way we could deport 12 million aliens. It was hard enough moving 160,000 soldiers to Iraq. The government showed it was incapable of moving 225,000 people out of New Orleans. How could we move 50 times that many people out of the country?
Those who support these impossibilities also favor building walls or impermeable fences along the borders. Imagine: the same people who are unable to rebuild the 17th Street Levee in New Orleans now propose to build a wall five times as long as the Great Wall of China.
Or maybe it's only 1½ times as long as the Great Wall. After all, they are referring mainly to the US-Mexican border, not to all land borders or the whole perimeter of the country. If that is not the ultimate act of jingoistic and xenophobic extremism, I don't know what is.
Besides, a wall or fence would only discourage, not prevent, illegal immigrants from entering the country in the future. It would do nothing to address the question of what to do about those already here.
Some politicians back a "guest worker" program. Its essence is that Mexicans can live with their families in Mexico and cross the border daily to do jobs that are too distasteful, demeaning, disgusting, or low-paying for Americans to do. Thus, America gains the economic and social benefits of their labor without incurring the economic or social costs of their residency.