TALLAHASSEE — For all their differences on national issues, how Republican Marco Rubio and Democrat Patrick Murphy handle one uniquely Florida issue — pollution from Lake Okeechobee — could have a profound impact on the future of the state.

The two U.S. Senate candidates both say they're committed to Everglades restoration — and boast of accomplishments in Congress to prove that dedication — but they differ on how the problem should be solved.

The issue has been teed up as a pivotal one in the next two years as incoming Florida Senate President Joe Negron, R-Stuart, announced in August that buying land south of the lake in the heart of the Everglades Agricultural Area is essential to solving what he called the state's "environmental emergency."

Negron said it will be his top priority to get state and federal approval for $2.4 billion to buy the land so it can store and clean the lake water and prevent harmful, phosphorus-laden discharges.

Whoever is elected Florida's junior senator in November could greatly influence the congressional debate when Negron makes that pitch.

Against and for

Rubio, the incumbent U.S. senator, said last month he opposes seeking federal money to buy sugar land south of Lake Okeechobee as a way to stop the massive release of polluted water to the east and west, which spawned toxic algae blooms in the St. Lucie and Caloosahatchee estuaries this summer.

It is just one of the arguments Rubio makes that echoes the position of the sugar industry, which contributed $486,000 to Rubio's failed presidential bid, according to an analysis by TC Palm in July.

Murphy, however, supports the land buy and has made advocacy for Everglades restoration a prime focus for his tenure in Congress, where he's served two terms representing northern Palm Beach County and the Treasure Coast — including areas plagued by this summer's algae blooms. Murphy has received no sugar industry money and has been endorsed by several environmental groups in his bid to unseat Rubio.

For his part, Rubio isn't so much against the idea of buying sugar land as he has said he believes it's bad timing to ask now for more money from the federal government.

The U.S. Senate and House this month each passed plans to direct $1.9 billion to cleanup projects south of the lake and, before the Senate vote, Rubio argued it would be a bad idea to ask for more. He told the Times/Herald that the state cannot ask Congress for money to buy land until existing projects are funded "because we're not going to get both."

Murphy, meanwhile, told the Times/Herald in a statement this summer that Everglades restoration needs to be a collaborative effort between the federal and state governments. He said Congress needs to fulfill its obligation of fully funding projects, while Florida needs to use Amendment 1 funds to contribute its share of the cost to buy land for water storage and treatment areas.

When Democratic U.S. Sen. Bill Nelson suggested using eminent domain to seize land the sugar industry refuses to sell in order to avoid the economic havoc that resulted from the noxious and dangerous algae bloom, Murphy said that idea "would tie up all existing projects" to finance the litigation but that "no options should be off the table."

Long-term solution

Buying sugar land to build a reservoir is seen by environmentalists as the only long-term solution to the 30-year quest to restore clean, fresh water into the Everglades and ultimately Florida Bay — which has been in decline after decades of flood control has blocked the natural flow of water. The reservoir could also stem the discharges into the estuaries to the east and west of the lake.

In July, Rubio said regulators should store more water north of the lake because that's where most pollution comes from. It is the same argument made by sugar giant Florida Crystals and the Sugar Cane Growers Cooperative, which argue that other alternatives to handling the polluted water exist, such as injecting it deep underground.

Rubio also has repeatedly argued that buying land would take away money from existing projects.

"We are in a competition with 49 other states for water money, and if we keep coming up with new projects, what these other states will say to us is, 'Well, we're not going to fund your programs until you guys down there figure out what you really want,' " he said.

Funding priorities

Rubio and Murphy also differ on how attentive they have been at getting Congress to fund Everglades restoration projects.

In 2000, then-President Bill Clinton and then-Gov. Jeb Bush signed the historic Comprehensive Everglades Restoration Plan — agreeing to divide the cost of turning thousands of acres of farmland into stormwater treatment areas used to remove phosphorus.

The legislation called for funding restoration projects every two years with the renewal of the 2000 Water Resources Development Act, Congress' blueprint for regional water projects across the nation. But after the 2000 WRDA was adopted, Congress reneged on the deal. The next water bill was not passed until 2007 and another one wasn't passed again until 2014.

The 2014 bill included authorization for four Everglades restoration projects, totaling $1.89 billion — something Murphy has touted repeatedly on the campaign trail as among his top legislative achievements.

"Fighting to protect the Everglades and our waterways has been a top priority for me since I was first elected," Murphy said in a statement this week.

But Rubio's campaign — which is trying to paint Murphy as ineffective with no accomplishments — said that he "is embellishing his record on the Everglades" by taking credit for the money. The four projects had been approved by the Army Corps before Murphy took office and were already in line to be included in the next water bill.

"Partisan attacks on the Everglades have no place in Florida politics," Murphy spokesman Joshua Karp said in a statement, calling the criticism "disappointing."

What the 2014 water bill didn't include, however, was a $1.9 billion suite of projects — called the Central Everglades Planning Project, or CEPP — that were pulled from the original restoration plan. After more than a decade of delays, Florida's legislative delegation pushed the initiative as a way to achieve incremental progress by moving 14 percent of Lake Okeechobee discharges away from the estuaries by 2029.

It took the U.S. Army Corps of Engineers until December 2014 to sign off on CEPP, too late to make the bill that Congress had passed months prior.

To the Florida delegation's delight, CEPP is included in this year's water bill — an achievement for which both Rubio and Murphy claim credit. Rubio says he persuaded a pivotal senator to support it and Murphy says he "led the fight."

Although versions of the water bill cleared both the House and Senate this month, it is still incomplete, as congressional leaders must resolve small differences.

Who's fighting harder?

Many in Florida's environmental community say Rubio has been absent for much of this fight — with his contributions coming more recently. A timeline provided by Rubio's staff indicated his involvement began in 2013, a year before the water bill, and two years into his term. Murphy, by contrast, campaigned on the issue and has been an active advocate since he took office in January 2013, the environmentalists said.

When Murphy and U.S. Rep. Trey Radel, R-Fort Myers, arranged for a congressional briefing in October 2013 on the status of the Indian River Lagoon, Nelson and House Minority Leader Nancy Pelosi, D-California, attended — but Rubio was a no-show.

When the Army Corps delayed approval of CEPP in early 2014 — making it impossible to include in that year's water bill — Murphy led a bipartisan coalition of Florida's delegation urging the Corps to expedite its review. Four Republicans signed onto a letter to the Corps authored by Murphy, but Rubio was not one of them. He sent his own, individual letter, a month later.

Rubio and Murphy both also take credit for accelerating congressional action related to another project critical to Everglades restoration, Ten Mile Creek. The South Florida Water Management District had agreed to take over the program from the Army Corps in 2014, but it needed congressional authorization to do it. Both Rubio and Murphy pushed for the language but only Rubio's language was included in the 2015 budget bill.

In 2014, TC Palm strung together a list of Rubio's Everglades promises compared with his performance. The story — headlined "Indian River Lagoon advocates ask: Where is Rubio?" — noted that Rubio frequently sent his regional director, Greg Langowski, to tour the region and attend local meetings rather than Rubio appearing in person.

Eric Draper, executive director of Audubon of Florida, told Bloomberg News earlier this year: "Rubio has never been particularly helpful on Everglades issues in Washington."

Rubio in 2014 co-sponsored a bill with Nelson to authorize CEPP without a water bill. Murphy offered a similar version. Neither bill went anywhere.

Meanwhile, Murphy wrote letters to federal officials to prod them into approving and funding Everglades projects. When President Barack Obama flew to Fort Pierce for a golf weekend in April, Murphy greeted the president and handed him a bottle of brown St. Lucie River water as a reminder.

After the algae crisis captured national attention in July, Rubio visited the St. Lucie River in person. He then took to the Senate floor, warning his colleagues of the region's ecological disaster.

In an op-ed written for the Miami Herald and published on Sept. 8, U.S. Sen. Jim Inhofe, R-Oklahoma — the powerful chairman of the Environmental and Public Works Committee who had been a staunch opponent of Everglades funding for more than a decade — credited Rubio with persuading him to change his mind.

Inhofe initially announced his support of the funding just days before the Florida presidential primary in March when Rubio was trailing Republican front-runner Donald Trump. After Rubio sought re-election, Inhofe agreed to move up the vote on the bill to September — instead of after the November election.

"Despite the rigor he (Rubio) faced then on the presidential campaign trail earlier this year, he worked with others to reach out to me privately and explain the importance of the Everglades to his state," Inhofe wrote this month.

But environmentalists aren't buying that Rubio inspired Inhofe's sudden change of heart.

"It's politics at its finest, and its worst," said Kimberly Mitchell, executive director of the Everglades Trust, which has endorsed Murphy. "It obviously wasn't controversial since it passed 97-3, but if it means good projects get done, that is the benefit of an election."

Meanwhile, Rubio's campaign argues Murphy plays politics, too — noting that Murphy's congressional office this summer sought to delay news about federal relief for businesses in his district affected by the toxic algae so that he could be the one to announce it.

"You pull stunts like that when you don't have any actual accomplishments to run on," Rubio spokesman Michael Ahrens said.

Karp said the attacks from Rubio "come as no surprise" given the senator's record, such as not supporting the science of climate change.

"Floridians know they can't trust Rubio in the fight to protect our environment," Karp said.

Mitchell said Murphy earned the Everglades Trust's support because he "gets it" when it comes to the central issue: buying land in the Everglades Agricultural Area for water clean up.

"We have known for years that this is the most important piece to Everglades restoration," Mitchell said. "We also know it was going to be the hardest because of who owns the land."

Eric Eikenberg, CEO of the Everglades Foundation, the nonprofit advocacy organization which, unlike the Everglades Trust, cannot endorse in elections, said it is important to end the delays and find money now for clean-up and buying land.

"The issues of the Everglades have traditionally been bipartisan issues and what the Everglades needs is a senator from Florida who is ready to go on Day One to bring the federal money home to finish these projects," he said.

Mitchell commended Rubio's recent efforts to help obtain money for CEPP but she said his suggestion that the state also should not seek federal money to buy sugar land "is just flat wrong."

"Those other projects are important components to Everglades restoration but, without the reservoir, it doesn't solve the problem," she said. "For the last 16 years, they have been nibbling at the edges but none of it is getting to the heart of the problem. It's not an either-or — you have to have both."