Republican presidential contender Donald Trump joined Bret Baier on "Special Report" tonight and continued his tough talk on illegal immigration.

Baier pointed out that deporting millions of people, as Trump has promised, would be logistically very difficult and extremely expensive.

"They're here illegally. They have to go back," Trump stated.

Baier pointed out that in 2012 Trump criticized Mitt Romney's self-deportation plan as "crazy" and "too mean-spirited."

"I said it was crazy because it doesn't work," Trump said, explaining that he doesn't believe illegal immigrants will voluntarily leave. "I criticized it because it's something that doesn't work."

So your deportation plan is not mean-spirited? Baier pressed.

"I don't think it's mean-spirited. Mine is not mean-spirited," Trump said. "It's business. We have a country. You don't have a country if people are allowed to walk in, cross the border and stay here for as long as they want. You don't have a country."

Watch more from "Special Report" above.

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