TALLAHASSEE — The race for governor of Florida features two leading candidates voters increasingly see as deeply flawed with campaign strategies virtually alike: Tear down the other guy at every turn.

Republican Gov. Rick Scott and Democrat and former Gov. Charlie Crist, both of whom are expected to win their party primaries later this month, have spent more time criticizing each other than laying out a future vision on major issues such as water, climate change, gaming, property insurance, economic policy or taxes.

The candidates, their operatives and third-party groups relentlessly drive a message that their opponent is untrustworthy, unethical or incompetent. Their campaigns eagerly amplify the mud-slinging in news releases, social media messaging and television ads, and their policy papers lack details on a host of deadlines facing the next governor will face.

Political scientists, consultants and even former U.S. Sen. Bob Graham, who served two terms as governor, warn that the lack of vision in the governor's race spells trouble for Florida.

The campaign's negative tone is likely to alienate the state's rapidly growing pool of unaffiliated, no-party voters, they say. If turnout is suppressed, and the third-party candidate on the November ballot gets a significant slice of the vote, the winner could be elected by less than a majority — seriously impeding the next governor's ability to lead the state for the next four years.

"What frankly concerns me is it is going to be a very nasty election in which a lot of people will go to the polls asking which of these two bad choices is least bad,'' said Graham, a Democrat who was elected governor in 1978 and 1982 and served three terms in the U.S. Senate. "Nobody is going to be elected with anything that could be described as a mandate to do something."

Graham warned that if there are tough decisions before the Legislature on education, taxes, health or the environment, "neither candidate will be able to say, 'I ran in order to accomplish these goals; the people elected me. Now, Legislature, let's put our shoulder to the wheel and get it done.' "

J. M. "Mac" Stipanovich, a Republican political consultant who has served every Republican governor since former Gov. Bob Martinez, jokes that the noxious atmosphere will result in the winner being "carried on a stretcher to the podium to make his inaugural speech."

A politically-wounded governor will have his power shift to the Legislature, experts say.

"You can see the Legislature saying, 'You didn't come close to a majority. We're not going to pay any attention to you,' " said University of Florida political scientist Richard Scher who has studied governors for decades.

If the governor doesn't provide leadership direction, the GOP-led Legislature will have an outsized influence in setting statewide policy, said Darryl Paulson, professor emeritus of political science at USF St. Petersburg. "The real losers are going to be Floridians who won't be able to choose between competing visions."

Scott got a sense of how a weak governor can have his agenda shrouded by the Legislature in 2010 when he narrowly defeated Democrat Alex Sink. His early approval rating was a dismal 32 percent.

During his first two sessions, legislators paid lip service to much of his agenda and pushed their goals of Medicaid reform and a rewrite of the teacher tenure law. Centrists in the Legislature also pushed back when Scott wanted to overturn a court ruling that stopped him from privatizing more prisons, proposed reforms to bust unions and tried to crack down on companies hiring undocumented immigrants.

"On a good day, the Legislature not only didn't have to do what Gov. Scott told them, they didn't even have to take his calls,'' Stipanovich said.

The Republican leaders, whose party is expected to maintain its reins of the Legislature after the November elections, say they welcome the chance to take the lead on policy initiatives but are not ruling out the strength of a governor.

"Regardless of how a governor comes in, he still has the bully pulpit,'' said Sen. Andy Gardiner, R-Orlando, a strong Scott supporter who is designated to be elected Senate president after the November election. But Gardiner will have his own agenda, he said, and "we'll work very closely with the governor to get it done."

Rep. Richard Corcoran, a Republican from Trinity who is designated to be House speaker in 2016, believes the state House is better suited to set the agenda for the state than the governor anyway. "I have always felt that we're the body that should be promulgating an agenda and championing what the people want because we probably know it quicker and better than our counterparts in the Senate or the executive branch,'' he said.

Since he was elected in 2010, Scott has "grown in the office" and shifted away from his hard-line adherence to tea party policies to a ideology that is "more to the middle," Stipanovich said.

If elected to a second term on another narrow plurality of the vote, legislators may give him a warmer reception because they have watched him evolve and may be more willing to embrace his ideas, Stipanovich predicted. But Crist, the former Republican, "won't be given the time of day."

Crist, who frequently gets asked about how he would work with the Republican-led Legislature, says some of the verbal animosity from his former GOP colleagues is just for show. He tells the story of recently meeting a Republican legislative leader in an airport "and it was just the two of us in the Tampa airport — no audience, no media, no show."

"We had a very cordial conversation about the race," Crist recalled. "He said, 'If you win, I look forward to working with you.' So I think we'll be fine."

Crist blames Scott's massive campaign chest for forcing him to run a campaign that is always on the defensive. "I've got $100 million coming at me,'' he says. "The battle is monumental."

Scott and his affiliated fundraising committees have collected nearly $40 million so far, according to the latest campaign reports. Crist and his committees have raised nearly $20 million.

But rather than use the money to sell their ideas on a set of policy initiatives they can claim as a mandate, Scott and Crist have released modest agendas, vague details and allowed the campaign narrative to focus on the other guy's liabilities.

"They're both trying to say, 'I'm really not that person anymore, I'm somebody else,' and for both candidates to have that in the same election is really quite unusual," said UF's Scher.

In recent days, both campaigns have sprinkled their campaign attacks with a handful of policy announcements.

Crist has released a set of middle-class policy goals that promise to require companies that win state contracts to offer a minimum wage of $10.10. He announced a loan forgiveness program for college students in science, technology, engineering and math fields, and announced his "Fair Shot Florida" campaign aimed at developing middle-class opportunity through education and jobs. The proposal features several education-related initiatives, as well as expanding access to health care.

Scott last week rolled out a $1 billion spending plan to preserve the environment, an initiative that calls for investing $50 million a year for alternative water-supply projects and another $50 million a year for natural springs restoration.

When Crist was pressed for big-picture policy goals by the Miami Herald editorial board last week, he cited Medicaid expansion and a high-speed rail system as among two issues he would put political muscle behind as governor. Scott rejected federal high-speed rail dollars and did not press state lawmakers to approve Medicaid expansion, though he supports it.

The toxic tone and absence of a clear agenda has already colored voter opinions. Public disfavor with Scott has been evident since he took office, but the onslaught of negative ads from Scott and the Republican Party of Florida have hurt Crist's once-buoyant polls numbers.

The latest Quinnipiac University poll found that 51 percent say Scott is not trustworthy; 48 percent say Crist is not trustworthy. Scott's latest favorability ratings have shown modest improvement, but voters say he does not deserve a second term.

The Quinnipiac poll also showed 9 percent of voters favored Adrian Wyllie, a little-known Libertarian Party candidate who will share the Nov. 4 ballot with Crist and Scott, even though 92 percent of voters said they didn't know about him.

Wyllie's surprisingly strong showing increases the chance that he'll be included in three statewide TV debates, and that could improve his standing with voters.

If Wyllie's poll numbers turn into votes on Election Day, and turnout is low, neither candidate will come away with a mandate. Turnout in the 2010 governor's race was a lowly 49 percent compared to 72 percent of the electorate who turned out to vote in 2012, a presidential election year.

Paulson believes the absence of vision from the candidates is an opportunity lost.

"This should be the greatest opportunity for Floridians to have a choice between a former and an incumbent governor,'' he said. "And yet most Floridians are probably going to be plugging their noses on Election Day and saying, 'Is this the best Florida can do?' ''

Miami Herald staff writer Patricia Mazzei contributed to this report. Contact Steve Bousquet at sbousquet@tampabay.com. Follow @stevebousquet. Contact Mary Ellen Klas at meklas@MiamiHerald.com. Follow @MaryEllenKlas.