President Barack Obama's move to prevent thousands of young immigrants from being deported appears to have upended the push by Sen. Marco Rubio, R-Fla., for legislation that would do the same.

Obama's new immigration order addresses immigrants who were brought to the country illegally as children under 16 and have since abided by the law, enrolled in school or joined the military. They can now apply for immunity from deportation and for work permits.

A stalled Democratic bill, the Dream Act, would have offered those young undocumented immigrants a chance to become U.S. citizens. The Dream Act has been unable to surmount Republican opposition, most recently dying in the Senate when it failed to garner enough support to overcome a filibuster threat and get to a vote in late 2010.

Recently, Republicans have begun quietly discussing possible alternatives to the Dream Act. Rubio, a Cuban-American and an ascendant player in the party, had said he was working on a version of the bill that would offer legal status -- but not citizenship -- to some young undocumented immigrants. 

The crucial difference between the Dream Act and Rubio's legislation was the possibility of citizenship. Republicans have denounced the Dream Act as an amnesty that would encourage more illegal immigration, but Rubio had emphasized the need for a middle ground that rescued young immigrants from legal limbo.

You can legalize someone's status in this country with a significant amount of certainty about their future without placing them on a path towards citizenship, and I think that that is something we can find consensus on, Rubio said in March.

But the new Obama administration initiative has essentially accomplished that, eliminating the need for Rubio's measure. An anonymous Rubio aide told the Huffington Post the senator is now reconsidering introducing legislation, and a Rubio spokesman told Politico that Obama's shift takes a lot of momentum out of Sen. Rubio's push for a consensus, legislative solution.

Obama has continued to call for Congress to pass the Dream Act and pursue comprehensive immigration reform, stressing that the new directive is not a substitute for legislation. But Rubio has joined presumptive Republican nominee Mitt Romney in attacking Obama for enacting a politically motivated stopgap.

He's basically taking a very significant issue that needs to be solved in the long-term way that's measured, reasonable and balanced and decided by edict, by fiat basically, to shovel it in the short term, which happens to coincide with the November election, Rubio told Fox News' Sean Hannity. That's, I think in the long term, is going to have some very significant implications on this.

Rubio added that the move was for political reasons -- a near-certainty given the role the Latino electorate could play in several swing states. The Obama administration has come under criticism from Latinos and immigration advocates for pushing deportation to record levels while failing to advance meaningful legislation through Congress. Preliminary polls suggest that the fresh effort to shield young immigrants from deportation has already encouraged Hispanic voters.

Cognizant of the potential impact of those Latino voters, Romney has chosen his words carefully in responding to Obama's order. Rather than invoke amnesty or suggest Obama is breaking the law, he has spoken of the need for a long-term solution and has faulted Obama for not pushing for a bill when Democrats controlled both houses of Congress.

He also said that with regards to these kids who were brought in by their parents through no fault of their own, there needs to be a long-term solution so they know what their status is -- a notable softening of the harsher rhetoric he deployed during the Republican presidential primaries, when he said his immigration policy centered on encouraging self-deportation.

Romney had previously backed Rubio by calling for a Republican Dream Act. But Obama has effectively co-opted that option, putting the Republican presidential candidate in a precarious place between immigration hardliners and Hispanics who feel alienated by the party's tough-on-immigration approach.