We’re still 15 months away from Election Day 2020, but it’s never too soon to assess the vulnerability of Florida’s congressional delegation.

For the sixth straight cycle, we’ll be publishing assessments that rank Florida’s U.S. House districts in descending order, starting with the most vulnerable. We define “vulnerable” as the likelihood that the opposing party will seize control of the seat in 2020; the possibility of a loss by an incumbent in an intra-party primary does not factor into our calculations.

At this early point in the election cycle – before many of the challengers are known and before incumbents start to announce their retirements – we’ve sorted the districts into two categories, "vulnerable" and "potentially vulnerable." We may include additional categories as the cycle progresses. The seats in the delegation not listed below are not considered vulnerable at this time.

As of now, the state of play presents both parties with opportunities and vulnerabilities. Here’s our take:

Vulnerable seats

1. District 27: Rep. Donna Shalala (D)

Shalala, a veteran of Bill Clinton’s cabinet and former president of the University of Miami, flipped this majority-Hispanic district in Miami and Miami Beach when the Republican incumbent retired in 2018. But her margin of victory (6 points) was smaller than Clinton’s in 2016 (19 points), thanks to a strong candidacy by Spanish-language TV veteran Republican Maria Elvira Salazar. Early this month, Salazar announced that she will be making a second run against Shalala, which ups the competitiveness of the seat for 2020. While Shalala’s comparatively weak ties to the Latino community hurt her in 2018, she is considered a strong fundraiser and starts with $547,871 in the bank. Expect a high-spending, high-profile race in an expensive district.

2. District 15: Rep. Ross Spano (R)

Spano won an open seat in 2018 in a district that went for Donald Trump in 2016 by 10 points. But he faced turbulence almost from the moment he won the suburban Tampa and Lakeland seat after it came to light that he had improperly accepted $180,000 in campaign donations from two friends; Spano acknowledged his error, saying he was given bad advice. As of June, Spano reported a worryingly small amount of money in the bank, just $160,000. Despite the GOP lean of the district, Democrats are encouraged by the candidacy of state Rep. Adam Hattersley, who served in Iraq in the Navy and earned a Bronze Star.

3. District 26: Rep. Debbie Mucarsel-Powell (D)

In 2018, Mucarsel-Powell defeated incumbent Republican Rep. Carlos Curbelo by two points in this heavily Cuban district in Miami-Dade and the Florida Keys. She begins with an edge; the district backed Hillary Clinton in 2016 by 16 points. Still, the Democratic gubernatorial and Senate candidates underperformed among Latinos in South Florida in the 2018 midterms, giving Republicans hope that they may be able to flip the seat back next year. Curbelo opted not to try again in 2020, leaving the GOP with one early contender, Irina Vilariño, a prominent co-owner of Cuban restaurants whose family’s emigration story dovetails with the GOP’s strategy of painting Democrats as socialists. Democrats see Vilariño as having a Trumpier style than Curbelo, which could be a problem in a district that went so heavily for Clinton. Vilariño has almost $256,000 in the bank, but Mucarsel-Powell has proven to be an impressive fundraiser, with $934,000 on hand.

4. District 16: Rep. Vern Buchanan (R)

Despite being targeted by Democrats in 2018, seven-term incumbent Buchanan ended up winning the race in his Sarasota-based district by 10 points, the same margin Trump won the district by in 2016. Republicans don’t see the seat as especially competitive, given the district’s GOP leanings and Buchanan’s deep pockets. But Democrats have secured probably the strongest candidate they could have gotten for the race: Margaret Good, who won a 2018 special election for a state House seat that overlaps with the district (defeating Buchanan’s son James to win it), then securing a term of her own in the fall.

Potentially vulnerable seats

5 (tie). District 18: Rep. Brian Mast (R)

Mast, an Army bomb-disposal expert in Afghanistan who lost both legs below his knees, was re-elected in a competitive contest in 2018, winning by 8 points in his Palm Beach-Treasure Coast district. With that kind of result in a favorable electoral environment for Democrats, Mast starts off as a strong favorite to win another term. He’s taken some heterodox positions for a Republican on guns and the environment, and he has $624,000 in the bank. Democrats are looking to recruit a candidate to run in the 18th, but none has materialized yet.

5 (tie). District 7: Rep. Stephanie Murphy (D)

Murphy, a Vietnamese-American former refugee, is a rising figure in national Democratic circles and has pitched herself as a moderate. Her Orlando-area district voted for Clinton by seven points and is home to a substantial Puerto Rican population. Murphy has almost $624,000 in the bank and won in 2018 by an impressive 16-point margin, giving her a strong edge. Republicans promise to find a challenger, but any GOP candidate would start the race as an underdog.

7 (tie). District 6: Rep. Mike Waltz (R)

This Republican-leaning Daytona Beach-St. Augustine district has been moving away from the Democrats. The party’s credible 2018 nominee, foreign-policy expert Nancy Soderberg, ended up losing to Waltz in an open-seat contest by 12 points. The Democrats don’t have a candidate yet; the Republican incumbent starts out as a strong favorite.

7 (tie). District 13: Rep. Charlie Crist (D)

Crist is a fixture in Florida politics – virtually everyone who’s voted in the state in the past two decades has voted for him as either a Republican, an Independent, or a Democrat (his current affiliation). That makes it hard to imagine him losing his St. Petersburg-Clearwater seat in 2020. Nonetheless, Republicans have assembled a surprisingly large field to take on Crist, including such stronger-than-usual challengers as Amanda Makki, a former congressional aide whose family emigrated from Iran, and Matt Becker, who was chief operating officer of the 2012 Republican National Convention in Tampa. But Crist is sitting on an impressive campaign war chest of nearly $2.3 million.