"Better work, better opportunities, more money," one captured illegal immigrant said. "They can catch me one, two, three, four, five times. Ten times. I'm going to cross."
Another said he'd keep trying until he got there with his family. "It doesn't matter to me. I'll cross again and I'll cross again. That's all."
A Brookings Institute survey of thousands of migrants who came to the U.S.-Mexico border found that more than nine out of 10 were able to enter, if not on the first try then on the second or third try.
And even if we built an impenetrable fence, one that's a mile high, it would only solve part of the problem, because lots of undocumented migrants don't sneak in. In fact, nearly half of illegal immigrants who are now in America came here legally through border checkpoints or they flew here and overstayed a tourist visa or a student visa.
A fence won't have any effect on them.
The 9/11 terrorists came here on tourist and student visas. They flew to America, legally. And yet you taxpayers continue to pay for construction of the border fence.
In an interview with "20/20," Drew Carey, who hosts Reason TV, said, "I don't know how anybody can't see that this stupid fence isn't a waste of money."
When Hunter retired from Congress this year, his son Duncan D. Hunter won election to his seat in the fall. He agrees with his father that we need a barrier on the southern border.
"What is it worth to the American people to not have another 9/11?" he said.
But wait a second. The border wall wouldn't have stopped 9/11.
"No," Hunter said. " But it might stop the next 9/11, or something like it."
But if it's good to wall off America, why just a wall on part of the Mexican border? What about the northern border? According to the Department of Homeland Security, last year more illegal Middle Eastern nationals were caught crossing from Canada than from Mexico.
And if we wall off Canada, we're still not covered. What about the miles of East and West Coast beaches? Are we going to have machine guns on the beaches?
The elder Duncan Hunter said that was silly. "Nobody's ever suggested doing anything mean. I think the message is this, if you want to come into the United States, which has the biggest front door in the world, you've got to knock on the front door."
But Carey points out, America doesn't make it easy to knock.
"It's so hard to get a guest worker permit and all this stuff. There's so many red tape hoops you have to jump through. It's easier to sneak across the border. We have to change it so the easiest, simplest thing isn't to sneak over the border. It should be if you want a job, you can come here and work. Get your papers and come in here and work."