Increasing--or at least persistent--tension in the Republican party over immigration? The Washinton Times has a story today about RNC Chair Mel Martinez criticizing Giuliani and Romney (and maybe others) for their opposition to the "grand bargain." The St. Petersburg Times's summary of Martinez's remarks:

"Presidential contests are about leadership. ... It's about leading on the tough issues," Martinez told the St. Petersburg Area Chamber of Commerce. "It was easy to say, 'This wasn't good enough, this isn't right, I don't agree with Martinez.' ... But at the end of the day what is your answer? How would you solve this?"

In his remarks, Martinez did not directly refer to former Massachusetts Gov. Mitt Romney or former New York Mayor Rudy Giuliani, but he later suggested both candidates, who were critics of the controversial Senate immigration proposal, had mischaracterized the plan.

Well, Giuliani has announced his own plans (though some opponents of the "grand bargain" are skeptical about these plans).
Random theory: if some Bush insiders believe (as some critics believe) that Giuliani's immigration policy may be, in significant ways, a continuation of the president's, could this criticism of Giuliani be an attempt to make it seem as though he is "tougher" on immigration enforcement: many critics of the administration's approach to immigration policy have focused on the lack of enforcement and the president's attempt to offer a "pathway to citizenship" to the "undocumented," so if the Bush-picked Martinez is criticizing Giuliani (who also supports a "pathway" and has been criticized for his immigration record while mayor of NYC), then he must be "tougher" on immigration enforcement! This criticism could give Giuliani an appearance of difference of opinion with the president over immigration (something, it seems, that much of the Republican base--and, perhaps, the nation as a whole--would like)--even if there may not be that much of a difference in actual policy. But there may also be significant differences; time will have to tell. Maybe Giuliani's immigration advisers will weigh in on this issue.
Of course, Martinez may just be angry about the difficulties the "grand bargain" has faced and be striking out at two opponents of the "bargain." In any case, his remarks do show some tensions in the national GOP over the "grand bargain" and immigration policy as a whole...