Many who have commented on the immigration issue, including me, have assumed that it's logistically and politically impossible to deport the estimated 12 million illegal immigrants in the country.
I'm not saying that it's a good idea, but for the sake of argument, I did the math. Assuming there are 12 million illegal immigrants and one wanted to deport them over a 3-year period, that would be four million deportations a year, or 333,333 per month. Rounding to 300,000, tht's 10,000 a day. At fifty passengers per bus, that would be 200 busloads per day. Dividing these over 10 border crossings (2 in San Diego, Tecate, Mexicali, Yuma, Douglas, 2 in El Paso, Nuevo Laredo and Brownsville), we average only 20 buses per crossing, or less than one per hour.
If we were to replace some of the buses with airplanes, the burden would be even less.
The cost of people to round up all the deportees, to process them (setting aside the question of legal process and attendant costs and delays), and hold them so they would not melt away once apprehended is another matter, as is the question of whether the media and the political system would be obstacles to such a process.
The physical process of deportation, however, is not impossible.
Obviously, there's no point to it, unless we fence the border and stop releasing arrested illegal aliens on bail, which means new holding facilities. Requiring identification for, or taxing remissions of funds, might also be an effective step.
This hypothetical has assumed that all illegals came through Mexico. Not so. Many are Asian and European and stay by overstaying legal visas. These folks have to be repatriated by plane.
The problem of mass repatriation is not logistical. It's political.