Are Democrats doomed to lose Florida? Start work now to avoid national heartbreak in 2020.

When Ron DeSantis was sworn in as the 46th governor of Florida last month, Sunshine State Democrats hung their heads in disbelief, having once again lost a critical statewide race by the slimmest of margins. Democrats across the country picked up seven governorships and 40 House seats, yet Tallahassee Mayor Andrew Gillum came up short in the gubernatorial race by just 0.4 percentage points. And Sen. Bill Nelson — who had been one of the few statewide Democratic standard-bearers over the past two decades — was unseated by Republican Rick Scott by 10,000 votes out of more than 8 million cast.

The blue wave that had swept across the country had once again crested before reaching Florida's shores.

Close Florida losses are always followed by analysis and blame. In the 2000 presidential election, it was hanging chads; in the 2010 gubernatorial race, it was Obamacare; in the 2014 gubernatorial race, it was Zika; and now in 2018, it was a faulty ballot design in Broward County.

Yet questions remain: Why do Florida Democrats keep coming up painfully short in what is theoretically the nation's premier swing state? Is Republican targeting, polling and outreach that much better?

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I'm a former Florida congressman and my vote was rejected over a signature 'mismatch'

As the Democratic nominee against Marco Rubio in the 2016 U.S. Senate contest, I experienced firsthand the heartbreak of a  statewide loss. Despite receiving virtually every single newspaper endorsement and promoting a message of working across the aisle, the negative attacks and outside money kept coming. I ran against Donald Trump's brand of divisiveness and had internal polling showing a competitive race, but the campaign ended in more Florida despair.

Democrats can and should do better, starting in 2020 with our presidential nominee. Here are the issues we need to address to win statewide.

Don't ignore voters in nonelection years

First, the immense size of the state makes it nearly impossible to campaign without tens of millions of dollars committed. With 10 TV markets across two time zones, it'll cost upwards of $2 million a week to hit each of them with campaign ads. And that's before you take into account digital ads, radio ads and campaign mail.

Second, Florida has an extremely diverse population, and turnout among voters of color is unpredictable — especially in midterm years. Cubans have been historically loyal to the Republican Party, while newer Democratic-leaning voters from Puerto Rico and Central and South America are still growing in political clout. These groups are not monolithic, certainly not on the subject of immigration, and they require more than an election-year touch to stay active. African-American voters, many of whom live in major metro areas like Miami and Jacksonville, are also often ignored until October of the election year.

Third, it takes a disciplined candidate to deliver a message that resonates in the many disparate regions of Florida. One might think of Florida as an amalgam of six or seven states, each with its own distinct attributes and cultures. There are Democratic-leaning snowbirds In Palm Beach, Republican-leaning retirees in the Villages and millions combined in the Panhandle, Central Florida and the Keys in between.

Democrats can't afford another heartbreaker

Democrats thought they had found the winning combination in 2018 — the stalwart Nelson would appeal to the moderates and rural voters who had kept him in office for a generation, while the liberal Gillum would turn out progressives and minority voters at a historic rate. Yet despite a national electorate that leaned almost 9 points Democratic, both fell short.

There's no silver bullet to this dilemma, but Democrats must solve it soon if we hope to remain competitive. We need to engage minority voters effectively, and not just in election years. We need to sustain a grassroots volunteer and fundraising base that can be tapped into every cycle. We need to support a bench of future statewide candidates who can appeal to the myriad communities across the state. We must register thousands of ex-felons whose voting rights were recently restored via ballot initiative.

And we need to fight for votes in the small towns that dot Florida along Interstate 95 and the I-4 corridor, not just in the major population centers. Is it any wonder voters there have turned so completely to the GOP? There is no reason the Democrats' economic message can't compete with the Republican pitch.

Until we find a formula that works, Florida Democrats will slink behind our counterparts in Arizona, Georgia and North Carolina on the presidential swing-state circuit. The 2020 race is just around the corner, and we can't afford another heartbreaking loss with so much at stake both here in Florida and across the country.

Patrick Murphy, a senior fellow at Florida International University in Miami, represented Florida's 18th district in Congress from 2013 to 2017 and was the Democratic nominee for the U.S. Senate in 2016. Follow him on Twitter: @PatrickMurphyFL