Marco Rubio and Ted Cruz tussled a few times in last night's debate , bringing into focus some of the policy divisions within the Republican Party. But do the two men really represent different factions? That depends on whether they really represent the positions they took.

No issue highlights those questions more than immigration. Rubio contributed to the 2013 "Gang of Eight" bill that would have provided for immediate legal status for illegal immigrants, although citizenship wouldn't have been available to them until (unspecified) measures were taken to strengthen border security. Asked about that bill during last night's debate, Rubio pledged he'd learned his lesson :

"It takes at least 20,000 more additional border agents. It takes completing those 700 miles of fencing. It takes a mandatory e-verify system and a mandatory entry/exit tracking system to prevent overstays. After we have done that, the second thing we have to do is reform and modernize the legal immigration system. And after we have done those two things, I think the American people are gonna be reasonable with what do you do with someone who has been in this country for 10 or 12 years who hasn't otherwise violated our laws -- because if they're a criminal they can't stay. They'll have to undergo a background check, pay a fine, start paying taxes. And ultimately, they'll given a work permit and that's all they're gonna be allowed to have for at least 10 years. But you can't get to that third step until you have done the other two things, and that was the lesson we learned in 2013. There is no trust that the Federal Government will enforce the law. They will not support you until you see it done first."

Unlike a number of Republicans, however, Rubio says he's still "personally open" to allowing today's illegal immigrants eventually to obtain citizenship. He acknowledged that "may not be a majority position in my party."

Cruz, on the other hand, has gone to great lengths to place himself in the Donald Trump/no "amnesty" wing of the party. But Rubio claimed last night that Cruz has in fact been in favor of legalization for illegal immigrants -- though not citizenship -- in the past. Here's how Cruz responded and Rubio followed up (with edits of some of the cross-talk among them, other candidates and CNN's Dana Bash for clarity's sake):

"He was fighting to grant amnesty and not to secure the border, I was fighting to secure the border. And this also goes to trust, listening on to campaign trails. Candidates all the time make promises. You know, Marco said, 'he learned that the American people didn't trust the federal government.'"

RUBIO: "Does Ted Cruz rule out ever legalizing people that are in this country now?"

BASH: "Senator Cruz?"

CRUZ: "I have never supported a legalization..."

RUBIO: "Would you rule it out?"

CRUZ: "I have never supported legalization, and I do not intend to support legalization. Let me tell you how you do this, what you do is you enforce the law..."

Cruz is catching it from two directions today for that last bit about "have never supported" and "do not intend to support" -- the latter from folks who feel like he's leaving the door open to changing his mind. But most of the focus is on the former statement, which is at odds with the historical record.

At issue are a series of amendments to the Gang of Eight offered by Cruz back in 2013. Among them was a provision to block citizenship -- but not legalization -- for those illegally present in the country at the time. Here's what he said shortly after the fight over the bill to the Washington Examiner's Byron York:

"'In introducing amendments, what I endeavored to do was improve that bill so that it actually fixes the problem,' Cruz told (York). 'I think an overwhelming majority of Americans in both parties wants to see our broken immigration system fixed, wants to see the problem solved, the border secured, and our remaining a nation that welcomes and celebrates legal immigrants. Given that bipartisan agreement outside of Washington, my objective was not to kill immigration reform but to amend the Gang of Eight bill so that it actually solves the problem rather than making the problem worse.'"

Also in May 2013, Cruz spoke at his alma mater, Princeton University, and talked about the bill and his amendments :

"The final two amendments were, number one, the one we just talked about, a bill that provided those here illegally would not be eligible for citizenship. Now, now, it's worth thinking for a moment about how that would operate. That's an amendment to the underlying bill. The underlying bill from the Gang of Eight provides for legal status for those who are here illegally. It provides for them getting a temporary visa initially, and ultimately being able to get a green card, as a legal permanent resident. The amendment I introduced would not change any of that, which would mean the 11 million who are here illegally would all come out of the shadows and be legalized under the Gang of Eight's bill. It would simply provide that there are consequences for having come illegally, for not having followed the legal rules, for not having waited in line, and those consequences are that those individuals are not eligible for citizenship."

National Review's Jim Geraghty highlights an exchange that day between Cruz and Prof. Robert P. George:

"George followed up, 'If I've understood you correctly, you would actually grant current illegal immigrants, or at least some substantial portion of those who are here unlawfully, permanent status? Green card status? So this is not a deportation bill, proposal or self-deportation as Romney called it, or anything like that. The disagreement is about whether they should be granted citizenship, through some mechanism, through some process, not whether they should be moved from illegal status to legal status?'

"Cruz replied, 'The amendment I introduced affected only citizenship; it did not affect the underlying legalization in the Gang of Eight bill.'

"George followed up, 'Would your bill pass the House, or would it be killed because it was proposing "amnesty"?'

"Cruz replied,'I believe that if my amendments were adopted, the bill would pass. My effort in introducing them was to find solution that reflected common ground and fixed the problem.'"

That's a long way from what Cruz now claims his amendments were all about: providing a poison pill to reveal the bill was all about amnesty and citizenship and making sure it died. In fact, during that Princeton appearance he made the exact opposite case:

"(W)hat I believe is happening is that citizenship provision is designed, and the White House knows it's designed, to be a poison pill in the House [of Representatives] to torpedo the bill, because then the want to campaign in 2014 and 2016, and say, 'see those Republicans? They killed immigration reform.'"

Now, it's entirely possible that, like Rubio, Cruz has changed his position since 2013. If so, it would be an entirely reasonable for him to do, as long as he's willing to explain why, as Rubio did last night. All he would have to say is something along the lines of, "When I first got to Washington" -- he was elected in 2012 -- "I thought I could trust my colleagues in the Congress to make sure the enforcement measures were carried out before legalization took place. I no longer believe that's true, and that no bill can include any legalization measure until after the border has been secured." It would be a bit cynical, since it's highly unlikely any border-enforcement bill would pass without some kind of legalization provision, and it would box him into a bit of a corner if he were to be elected president. But at least he could claim it was just an honest change of heart. Instead, he seems to be making a dishonest case that he's always been against legalization, when his actions and public comments from just a couple of years ago indicate otherwise.

As it happens, I tend to agree more with Cruz's position -- or at least, his position in 2013 -- that legalization, but not citizenship, is in order for those illegally present here once border and visa enforcement is improved. But his apparent refusal to be honest about his past positions on the issue makes it hard for me to trust him.

UPDATE: Cruz was asked about this on Fox News last night and doubled down on his refusal to acknowledge that back in 2013 he was telling a very different story to anyone who would listen. This could become a real problem for him because he's arguing against his own words, recorded multiple times by multiple people at the time. (When are politicians going to learn that everything is recorded, and while you can change your mind you can't disavow what you've said in the past?)