Updated at 4:21 p.m.

Just hours after word leaked out that the Obama administration would stop deporting young illegal immigrants who were brought to the United States by their parents, the issue is already causing headaches for the Republican Party.

The party, which has previously split over its own president’s efforts on illegal immigration reform, is similarly stuck when it comes to Obama’s decision.

And at a time when party unity is paramount, the move is exposing fissures.

This photo provided by the U.S. Immigration and Customs Enforcement, Wednesday, March 28, 2012, in New Jersey, shows agents taking a person into custody during operation Cross Check III. (AP Photo/U.S. Immigration and Customs Enforcement)

The company line from Mitt Romney’s presidential campaign and prominent senators like Marco Rubio (R-Fla.) and Lindsey Graham (R-S.C.) Friday was a process argument, in which they decry the decision to make the move without Congress’s consent.

“I believe the status of young people who come here through no fault of their own is an important matter to be considered and should be solved on a long-term basis so they know what their future would be in this country,” Romney said in a statement to reports in Milford, N.H. ”I think this action that this president took today makes it more difficult to reach that long-term solution, because an executive order is of course just a short-term matter.”

A statement from Rubio made a similar argument: “Today’s announcement will be welcome news for many of these kids desperate for an answer, but it is a short-term answer to a long term problem. And by once again ignoring the Constitution and going around Congress, this short-term policy will make it harder to find a balanced and responsible long-term one.”

Both responses, you’ll note, don’t take a much of a position on the substance of Obama’s move (though Rubio’s comes close to supporting it). And that’s deliberate.

In fact, while talking about the decision today, Romney aides repeatedly pivoted to talking about the economy instead. Romney’s campaign, clearly, would rather not take the focus off the economy for one second. The candidate did not take questiosn after delivering his statement.

The problem with that strategy is members of Congress like Rep. Steve King (R-Iowa).

King, one of the most outspoken Republicans on the issue of border security and illegal immigration, is now saying he will sue the Obama administration over the policy. While he agrees with Romney and Rubio that this raises issues of congressional prerogatives, he’s taking it a big step further.

“I’m prepared to bring a suit and seek a court order to stop implementation of this policy,” King said on Mike Huckabee’s radio show.

Other immigration hawks in the GOP were also quick to decry the decision.

“It rewards law-breaking,” said Rep. Jim Sensenbrenner (R-Wis.). “And it’s deeply unfair to those who came to this country legally.”

The fact is that there are all manner of conservative members of Congress who are more than happy to prosecute this issue in the coming hours and days — even as Romney would rather not.

But it’s not even just the conservatives in Congress that may cause Romney some problems here. Even former Mississippi Gov. Haley Barbour — a team player if there ever was one — said early Friday that he differed from the GOP presidential candidate on the issue.

“I would just have a different policy from what he has espoused,” Barbour said at a breakfast hosted by the Christian Science Monitor, adding: “We need to recognize we are not going to deport 12 million people and ... we shouldn’t.”

Words like this are fuel on the fire. Obama provided the kindling, knowing that Republicans would take it from there.

The fact is that Romney’s position is different from King’s, Barbour’s and even those he ran against in the GOP presidential primary, who criticized his so-called “self-deportation” policy. And he’s now going to be put in a position of answering questions about just where he and his party stand.

Keep an eye on his appearance Sunday on CBS’s “Face the Nation.”