"I am the party leader. I've got concerns," the governor said in response to a reporter's question. "The campaign can't be about her. It has to be about Bill Nelson and the future of our state and so far, she asked my advice and I gave her that exact advice and it's gotten worse since."
The woman best known for certifying George W. Bush's 537-vote win in Florida in the disputed 2000 presidential election has struggled in her bid to unseat Democratic Sen. Bill Nelson. Republican leaders showed scant enthusiasm for her Senate run after two terms in the House, and her top adviser, campaign manager and communications director recently resigned.
Harris, Florida's former secretary of state, also has had difficulty raising money. She pledged to spend $10 million of her own money to continue in a contest that polls show her trailing badly.
Harris didn't immediately return a call for comment.
The filing deadline for the state primary is May 12, which would give Harris time to exit the race. But GOP efforts to persuade other Republicans to compete in the Sept. 5 primary have been unsuccessful.
The governor said he has not been asked by anyone in Washington or the Republican Party to intervene.
"I'm just giving you a candid opinion of where the race is today," he said. "It can be turned around."
Tom Slade, who led the Florida Republican Party's resurgence in the 1990s and is a one-time mentor to Harris, said the constant campaign staff reshuffling has been costly.
"The contradictions and the starts and stops just don't add up to anything but utter and total confusion," Slade said. "This here-we-go, now-we-don't kind of stuff is just not compatible for a campaign for the U.S. Senate."
Her campaign became more difficult after a defense contractor involved in a bribery scandal said he gave $32,000 in illegal contributions to her 2004 campaign for the House.
Harris said she did not knowingly do anything illegal and said she would donate the money to charity.