Here is some evidence that supports my view:
Eight years after the Sept. 11 terrorist attacks and despite repeated mandates from Congress, the United States still has no reliable system for verifying that foreign visitors have left the country.
Last year alone, 2.9 million foreign visitors on temporary visas ... checked in to the country but never officially checked out, immigration officials said.
Over all, the officials said, about 40 percent of the estimated 11 million illegal immigrants in the United States came on legal visas and overstayed.
So why bother with border security at all? The costs are enormous: in addition to the expenses for immigration officials, border fences, and the like, millions of people lose time every day, all for a process that has no plausible chance of accomplishing its goals.
Open the borders officially. They are already open in reality.