Part of that was because of a drop in Democratic support among Latino voters. In 2016, 62 percent of Florida’s Latino voters broke for Mrs. Clinton, according to exit polls; two years later, just 54 percent voted for the Democratic governor and Senate candidates.
Mr. Trump has worked to strengthen his support among Cuban-Americans in particular, and his claims that Democrats are flirting with socialism may carry a particular resonance with these voters, many of whom belong to families that fled the Castro regime. But it was not only among Cuban Latinos that Democrats’ margins suffered in 2018.
While the Democratic vote generally rose elsewhere, in the three Florida counties with the highest Hispanic populations, it was down compared with two years earlier. One of those counties, Miami-Dade, has a high concentration of Cubans, but the others, Osceola and Hendry, are more heavily Puerto Rican and Mexican-American.
Mr. Biden was not the Latino community’s first choice in the Democratic primaries, and his lead over Mr. Trump among Latino voters has been unreliable since he became the nominee. That’s been particularly true in Florida, where some polls have shown him effectively tied with Mr. Trump.
“We’ve known for a while that Biden was unlikely to hit Clinton’s 2016 numbers, but the goal would be to do better than Nelson and Gillum did in 2018 and be more in line with where Obama was in 2012,” said Carlos Odio, a founder of EquisLabs, a liberal-leaning Latino research firm. That year, exit polls gave President Barack Obama a 21-point lead over Mitt Romney.
So far, Mr. Biden has not managed that. Averaging together the results of the Monmouth, Marist and Quinnipiac polls this week, Mr. Biden led by just 12 points among Latinos.
Latino voters now account for about one in five ballots cast in Florida, twice their share just 20 years ago.