With the announcement in Orlando, McCollum immediately became the front-runner in the GOP race to succeed Crist, who has announced a run for the U.S. Senate, analysts told The Miami Herald.
"The hallmark of a McCollum administration will be access and inclusion," he said. "This administration will be one that doesn't look at partisan labels."
McCollum, a former U.S. congressmen, was elected attorney general three years ago after defeating Democratic state Sen. Walter Campbell. That win came after failing twice in two campaigns for the U.S. Senate against Republican Mel Martinez and Democrat Bill Nelson, the newspaper said.
If he were to win the GOP primary, McCollum's likely Democratic opponent would be Florida Chief Financial Officer Alex Sink.
His record of mixed success has prompted some analysts to question McCollum's strength with an increasingly diverse Florida electorate, but Jim Greer, chairman of the Republican Party of Florida, Monday gave him his full support, the Herald said.