Rubio would not say whether he was already being vetted by the Romney campaign when reports surfaced early Tuesday that he was not being considered.

“I’ve made a decision a long time ago not to discuss the process, and that’s not going to change today,” Rubio said on “CBS This Morning.” “I respect that process that Governor Romney’s going through. You know, I’m confident he’ll make an excellent choice.

“I think those of us who are involved in politics and supportive of him should give him the space to do that.”

Rubio’s comments were the first he’s made on the issue since Romney told reporters Tuesday that the Florida senator is being “thoroughly vetted” as part of the VP selection process.

The Florida senator, who has emerged as the GOP’s leader on immigration reform efforts, said he hasn’t discussed the issue with Romney since President Obama last week announced that his administration is scrapping plans to deport some illegal immigrants, a surprise move that Republicans called an election-year gimmick and a disingenuous way to address the issue.

“Immigration is a difficult issue. Both sides, I think, oversimplify it sometimes,” Rubio said, adding later that the way Obama announced the policy change “is going to make it harder for us to come up with the kind of balanced solution that I was working on and that others were working on with me.”

Those comments echo similar sentiments expressed Tuesday by House Speaker John A. Boehner (R-Ohio), who said the president’s decision “puts everyone in a difficult position,” because it will adversely affect bipartisan attempts to tackle immigration reform.

Rubio’s appearance was part of a nationwide promotional tour for his new autobiography, “An American Son,” which chronicles his childhood and fast rise in national politics. (Another Rubio-themed book, “The Rise of Marco Rubio,” by Washington Post reporter Manuel Roig-Franzia, also hit bookshelves this week.). As part of the book tour, Rubio is slated to appear as the lead guest on NBC’s “Meet the Press” this Sunday.

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