MIAMI — Gov. Charlie Crist has been jawboned and buttonholed as he has traveled around the state in recent days, and his office was deluged with 120,000 messages. Passions have not run so high in Florida, the governor said, since the controversy over ending the life of Terri Schiavo in 2005.

This time, the point of contention was eliminating tenure for Florida public school teachers and tying their pay and job security to how well their students were learning.

On Thursday, Mr. Crist picked a side, vetoing a bill passed last week by the Florida Legislature that would have introduced the most sweeping teacher pay changes in the nation.

The veto puts Mr. Crist, a moderate Republican, at odds with his party base in the Republican-controlled Legislature. His decision has also renewed speculation that he might drop out of the Republican primary for a United States Senate seat and run in the general election as an independent. For months, he has been trailing the more conservative Republican candidate, Marco Rubio, a Tea Party favorite, in polls.