MIAMI BEACH, Fla. — On a recent afternoon, Scott McKenzie watched torrential rains and a murky tide swallow the street outside his dog-grooming salon. Within minutes, much of this stretch of chic South Beach was flooded ankle-deep in a fetid mix of rain and sea.

“Welcome to the new Venice,” McKenzie joked as salt water surged from the sewers.

There are few places in the nation more vulnerable to rising sea levels than low-lying South Florida, a tourist and retirement mecca built on drained swampland.

Yet as other coastal states and the Obama administration take aggressive measures to battle the effects of global warming, Florida’s top Republican politicians are challenging the science and balking at government fixes.

Among the chief skeptics are U.S. Sen. Marco Rubio and former Gov. Jeb Bush, both possible presidential candidates in 2016. Gov. Rick Scott, who is running for re-election, has worked with the Republican-controlled Legislature to dismantle Florida’s fledgling climate change initiatives. They were put into place by his predecessor and current opponent, Democrat Charlie Crist.

“I’m not a scientist,” Scott said, after a federal report pinpointed Florida – and Miami in particular – as among the country’s most at-risk areas.

He and other Republicans warn against what they see as alarmist policies that could derail the country’s tenuous economic recovery.

Their positions could affect their political fortunes.

Democrats plan to place climate change, and the GOP’s skepticism, front and center in a state where the issue is no longer an abstraction.

Their hope is to win over independents and siphon some Republicans, who are deeply divided over global warming. Tom Steyer, a billionaire environmental activist, has pledged to spend $100 million this year to influence seven critical contests nationwide, including the Florida governor’s race.

The battle in the country’s largest swing state offers a preview of what could be a pivotal fight in the next presidential election.

Crist is running for his old job as a Democrat, criticizing Scott and Florida Republicans for reversing his efforts to curb global warming.

“They don’t believe in science. That’s ridiculous,” Crist said at a recent campaign rally in Miami. “This is ground zero for climate change in America.”

Nationally, the issue could prove tricky for Democrats.

Polls show a bipartisan majority of Americans favor measures to reduce planet-warming greenhouse gases, such as the new federal rule to limit carbon emissions from power plants. But they routinely rank climate change far behind the economy, the centerpiece of Scott’s campaign, when prioritizing issues.

In Miami Beach, which floods even on sunny days, the concern is palpable. On a recent afternoon, McKenzie pulled out his iPad and flipped through photos from a 2009 storm. In one, two women kayak through knee-high water in the center of town.

“This is not a future problem. It’s a current problem,” said Leonard Berry, director of the Florida Center for Environmental Studies at Florida Atlantic University and a contributing author of the National Climate Assessment, which found that sea levels have risen about 8 inches in the past century.

Miami Beach is expected to spend $400 million on an elaborate pumping system to cope with routine flooding. To the north, Fort Lauderdale has shelled out millions to restore beaches and a section of coastal highway after Hurricane Sandy and other storms breached the city’s concrete sea wall. Hallandale Beach, which lies on the Atlantic Coast between the two cities, has abandoned six of its eight drinking water wells because of encroaching seawater.

By one regional assessment, the waters off South Florida could rise another 2 feet by 2060, a scenario that would overwhelm the region’s aging drainage system and taint its sources of drinking water.

“It’s getting to the point where some properties being bought today will probably not be able to be sold at the end of a 30-year mortgage,” said Harold Wanless, chairman of the geological sciences department at University of Miami. “You would think responsible leaders and responsible governments would take that as a wake-up call.”

Florida lacks a statewide approach to the effects of climate change, although just a few years ago, it was at the forefront on the issue.

In 2007, Crist, then a Republican, declared global warming “one of the most important issues that we will face this century,” signed executive orders to tighten tailpipe-emission standards for cars and opposed coal-fired power plants.

Bush, his predecessor, had pushed the state during his administration to diversify its energy mix and prioritize conservation.

Even Rubio, who was then Florida House speaker and a vocal critic of Crist’s climate plans, supported incentives for renewable energy. With little opposition, the GOP-led Legislature passed a bill that laid the groundwork for a California-style cap-and-trade system to cut carbon emissions and created a special commission to study climate change.

But the efforts sputtered as the economy collapsed and Crist and Rubio faced off in a divisive 2010 Republican primary for U.S. Senate.

Although Rubio had voted for Crist’s landmark environmental measure, he soon hammered the governor for what he called a “cap-and-trade scheme.” Seeking support from the growing tea party movement, he distanced himself from the vote.

Rubio also began to voice doubts about whether climate change is man-made, a doubt he shares with Bush. Both have stuck to that position.

Amid meetings with conservative activists and Republican leaders in New Hampshire last month, Rubio said: “I do not believe that human activity is causing these dramatic changes to our climate the way these scientists are portraying it.” Proposals to cut carbon emissions, he said, would do little to change current conditions but “destroy our economy.” Rubio later said he supports mitigation measures to protect coastal property from natural disasters.

Scott and Florida Republicans share his current views.

Denouncing “job-killing legislation,” they repealed Crist’s climate law, disbanded the state’s climate commission and eliminated a mandate requiring the state to use ethanol-blended gasoline. Asked about climate change recently, Scott demurred, saying the state has spent about $130 million on coastal flooding in his first term, as well as millions on environmental restoration.

Meanwhile, Miami Beach is bracing for another season of punishing tides.

“We’re suffering while everyone is arguing man-made or natural,” said Christine Florez, president of the West Avenue Corridor Neighborhood Association. “We should be working together to find solutions so people don’t feel like they’ve been left on a log drifting out to sea.”

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Associated Press writers Gary Fineout in Tallahassee, Florida, and Philip Elliott in Washington contributed to this report.

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