(BUMPED; UPDATES BELOW) St. Petersburg Times reports:

Republican Party of Florida Chairman Jim Greer, facing intense and growing backlash over meddling in the U.S. Senate primary, is backing off.

In a letter to party supporters [Wednesday], Greer defends his actions but said the party is now "neutral" in the contest between Charlie Crist and Marco Rubio.

Meanwhile, sources say grassroots Republicans in Texas are peeved at Sen. John Cornyn's endorsement of Crist. As Drudge says, DEVELOPING . . .

UPDATE 12:40 p.m.: Via Memeorandum, Erick Erickson reacts to Greer's walkback, saying the Florida chairman ""is glossing over the fact that he tried to use party rules to get Rubio knocked off the ballot. He is also ignoring the fact that he made clear at the RNC meeting that the Republican Party of Florida would be supporting only Crist in the Senate race and only McCollum in the gubernatorial race."

UPDATE 2:40 p.m.: John Hawkins and Erick Erickson issue a press release, and Beth Reinhard reports in the Miami Herald:

In response to a question about immigration, Rubio dropped his previous pleas against harsh attacks on illegal workers. He said he would not have voted in favor of the legislation -- backed by Crist and Sen. Mel Martinez -- that would have allowed illegal workers to earn legal status, which he called "blanket legalization."
"Nothing is more disruptive to legal immigration than illegal immigration,'' he said. "We must secure our borders."

Meanwhile, on the economic front, Charlie Crist was for Keynesian bailouts before he was against them. (Via Memeorandum.) And at Hot Air Green Room:

The question at stake, according to Aaron Marks of The Next Right, is "Who ultimately controls the GOP, the grassroots or the machine?" When the machine is run by "Chairman Bozo," as Florida conservative Javier Manjarres calls him, the odds favor the grassroots.

ALSO SEE:

• American Spectator: Texas, Florida Rumbling About Cornyn's NRSC Move
• Not One Red Cent: The Rebellion Goes Viral!
• Hot Air: Video: What Charlie Crist Is Up Against
• Green Room: Behind the 'Not One Red Cent' Rebellion
• American Spectator: Video: Interview With Florida Conservative Candidate Marco Rubio
• American Spectator: Florida Conservatives Slam NRSC Crist Endorsement