Stalling on Capitol Hill might force the president’s hand, the Florida Republican said. That could result in a mass legalization of undocumented immigrants without any of the reforms included in the Senate-passed immigration bill that Rubio played a key role in writing and negotiating. Rubio said continued delay in Congress could create a scenario in which the nation misses out on his bill’s technological advances along the border with Mexico, drones, cameras, more Border Patrol agents and a national E-Verify system.

There’s precedent for such a move by the White House, Rubio said: The 2012 decision to temporarily halt deportation of some young people after the DREAM Act got hung up in the Capitol.

“I believe that this president will be tempted, if nothing happens in Congress, he will be tempted to issue an executive order like he did for the DREAM Act kids a year ago, where he basically legalizes 11 million people by the sign of a pen. Now, we won’t get an E-Verify, we won’t get any border security. But he’ll legalize them,” the Florida senator told Tallahassee radio host Preston Scott.

Scott said his email was piling up during the show with messages critical of Rubio’s work on immigration reform, an effort currently on the back burner in the House of Representatives. Scott said listeners were asking why the laws on the books can’t just be enforced now. Rubio responded that the current laws are outdated, with little incentive for installation of a national employment E-Verify system and watered-down border security laws.

He called the current policy of “de facto amnesty” both “crazy” and “terrible” because the government knows little of undocumented immigrants’ criminal history and whether or not they are paying taxes. He said the legal immigration system is rooted in the past century, failing to track visitors and requiring skilled immigrants to jump through hoops more onerous than those moving to the United States because of family ties.

But most of all, Rubio emphasized Tuesday that he fears doing nothing at all will force President Obama’s hand — because without action from Congress, the country’s immigration problems will “only get worse as time goes on.”

“Unless we’re going to try to round up and deport 11 million people — something that not even the most vociferous opponent of the [Senate] bill proposed — then we are going to have to at some point address this issue,” Rubio said. “We can’t leave, in my mind, the way it is. Because I think a year from now we could find ourselves with all 11 million people here legally under an executive order from the president, but no E-Verify, no more border security, no more border agents, none of the other reforms that we desperately need.”