Marco Rubio's office got in touch this week to say the Florida senator and possible 2016 GOP presidential hopeful wanted to discuss immigration. The specific subject was President Obama's expected move to unilaterally legalize as many as half of the 11 million immigrants currently in the United States illegally. But Rubio, speaking by phone during a visit to Atlanta, had much more to say about the broader issue of immigration reform. What he outlined amounted to an entirely new approach to the issue that has contributed to his rise, then fall, and perhaps rise again, in the Republican Party.

Rubio began by saying he doesn't know what Obama will do on immigration, or when he will do it. The president, Rubio believes, is stuck between the activists who want him to take far-reaching action quickly and the red-state Democrats up for re-election who don't want to see anything done before November. Whatever course Obama takes, he'll do it without the counsel of one of the Senate's most knowledgeable voices on the subject. "I haven't spoken to the president about immigration in over a year," Rubio told me.

Even though Rubio doesn't know precisely what Obama will do, he can rightly say he has long predicted the president would take action without congressional approval. "I've been warning that he would do something unilaterally on immigration at some point, despite his denials of any intention to do that," Rubio said. "I've been warning that this is exactly what's going to happen."

It's true. During the debate over the Senate Gang of Eight comprehensive immigration reform bill, Rubio often argued that if Congress did not act on reform, then Obama would do something big on his own that would be far worse than any comprehensive bill, at least from a Republican perspective. "My fundamental warning was that if [Republicans] didn't like the legalization provisions in the bill, it was quite possible, if we didn't act, that we would get the Gang of Eight-style legalization but without any of the bill's enforcement mechanisms," Rubio told me.

Now that appears to be what is coming. And Rubio conceded that Republicans can't do anything about it unless they win control of the Senate in November — and even then, the GOP will have very limited options. "As long as Harry Reid is Majority Leader, the answer is nothing," Rubio said.

If the GOP does win Senate control and Obama takes unilateral action — a move Rubio believes would far exceed the president's constitutional authority — Rubio foresees Republican lawmakers voting to overturn the executive order (or administrative directive, if that's what it is). "That's something we would have to consider," Rubio said. "In fact, I think that's something I would advocate that we do in conjunction with putting in place meaningful reforms about how to enforce our immigration laws."

Of course, Obama would veto any legislation repealing his order, a veto Republicans would not have the votes to override. Still, Rubio argued that Obama's overreach could become a springboard for larger Republican action on immigration. If that happens, Rubio would like to see lawmakers take an approach to immigration reform far different from the Gang of Eight's comprehensive scheme.

Where the Gang of Eight provided for the immediate legalization of the 11 million immigrants in the country illegally, Rubio's new approach would insist that border security and internal enforcement be passed and implemented — put in place, not just contemplated — before Congress considered legalization. Only by establishing new security measures first can lawmakers win the trust of a skeptical public, Rubio argued.

"The fundamental impediment to making progress on immigration is that people in this country, a large number of Americans and their elected representatives in Congress, do not believe that, no matter what you put in the law, they don't believe the federal government will enforce it." If Republicans win control of the Senate, they can address those concerns only by "proving to the American people that illegal immigration is under control."

"To me, that means three things," Rubio continued. "Number one is investing in more strategic fencing, cameras, sensors and personnel on the border. Number two is an e-verify system every employer in America would be required to use before hiring anyone. And number three is an entry-exit tracking system that would allow us in real time to know who has overstayed visas."

Next, Rubio foresees "modernizing our legal immigration system towards one that is merit-based and works for the country." Only then, after new security measures and the legal reforms were both up and running, would Rubio advocate beginning a legalization process for the 11 million. "Once that's in place, and people see that it is working and is actually being applied," Rubio explained, "then I think people would be willing to have a serious and responsible conversation about how to address the millions of people who are here illegally, who have been here for a long period of time. But they're not willing to do that until they know that the illegal immigration problem is under control."

Rubio conceded that such assurances were simply not possible in a comprehensive bill, like the Gang of Eight, that included legalization from the get-go. "There is really no verification that you could put in a comprehensive bill that would assuage people's fears," he said, "especially now, given what's happened with the unaccompanied minor issue on the border."

The bottom line is that Rubio now freely admits the Gang of Eight bill, to which he devoted so much of his energy and for which he risked his standing in the party, was fatally flawed in light of today's political environment. Now, with the GOP presidential season approaching, he advocates a significantly different course — one that could be triggered by Obama taking the step Rubio predicted all along.