Sen. Ted Cruz reiterated his support for existing immigration law in a contentious interview Monday night. It was the second time the Republican presidential candidate appeared to stumble when asked on Fox News about rival Donald Trump's plan to deport all of the undocumented immigrants living in the country illegally.

In August, Fox host Megyn Kelly had tried to draw Cruz out on what he thought should be done about that group, which numbers nearly 11 million people. Cruz dismissed the question as a "distraction."

"I get that that's the question you want to ask," Cruz told Kelly. "That's also the question every mainstream media liberal journalist wants to ask."

Host Bill O'Reilly tried again in his segment Monday.

[A simple guide to what Ted Cruz really believes]

"Twelve million illegal aliens here in America -- Mr. Trump says he would deport them forcibly," O'Reilly said. "Would you round up 12 million illegal aliens here, and if so how?" (O'Reilly's estimate is a few years out of date. The undocumented population is now below 11 million.)

"Federal law requires that anyone here illegally that's apprehended should be deported," the senator from Texas replied. O'Reilly wasn't satisfied with that answer and pressed Cruz again a couple of times.

"Just let me get this straight, because this is very important," the host said. "Tommy O'Malley from County Cork in Ireland is over here, and he overstays his visa, and he's got a couple of kids, and he's settled into Long Island, and you, President Cruz, are going to send the feds to his house and take him out and put him on a plane back to Ireland?"

"You better believe it," Cruz said.

"This is my job: to get your position on the record," O'Reilly said. "We did it tonight." In fact, Cruz had said nothing more than what he's said in the past, but O'Reilly's confusion was understandable. Cruz has been consistent since he began the campaign, but his position is a difficult one to explain.

In essence, Cruz endorses the status quo regarding illegal immigration. In his view, federal authorities should continue deporting people who are here illegally, as they have been for years, and those undocumented migrants should not be eligible for citizenship, or even permission to stay legally, of any kind.

In some respects, Cruz believes that the Obama administration is not doing enough to remove undocumented immigrants. The Obama administration has deported a total of 2.5 million people through last year, many of them at the border. That's more than President George W. Bush deported during his full two terms in office.

Cruz, though, told O'Reilly that customs agents should have an electronic system to gather biometric information from foreigners entering the country, to help monitor them and identify those who stay beyond the dates on their visas. He has also proposed dedicating even more manpower and equipment to the southern border.

On the other hand, Cruz's proposal does not include a provision requiring businesses to electronically verify with the federal government their employees' eligibility to work. The senator has also rejected Trump's suggestion of a special force to seek out illegal immigrants in the interior, saying that while he'd hire more Immigration and Customs Enforcement agents, the existing bureaucracy is enough.

The unforgiving politics of immigration have prevented the senator from adopting a position further to the left -- like those of his rivals Sen. Marco Rubio (Fla.) or Ohio Gov. John Kasich, who support legalization of some form. Nor has he mimicked Trump's extreme rhetoric about mass deportation.

Instead, Cruz is playing it down the middle, arguing for a system like the one we have now, only somewhat enhanced: more Border Patrol agents, more fencing and closer monitoring of those who enter legally for a temporary visit.