DAVENPORT, Fla. (AP) — When Martha Santiago moved to Polk County, Florida, from Puerto Rico in 1979 to teach in one of the county’s first bilingual schools, there were two certainties.

One was that oranges were an economic engine in the county that is wedged between Tampa and Orlando. The other was that orange picking and other agricultural labor was done mostly by undocumented workers from Mexico.

Forty years later, Santiago is now Polk’s first Hispanic county commissioner. The fragrant citrus blossoms have been replaced by sprawling stucco subdivisions, and the Hispanic registered voter population in Polk County has boomed, with Puerto Ricans — who are U.S. citizens — driving the increase.

That transformation is a clear measure of the change in number, and the change in character of Florida’s Hispanic vote. One of the most important issues in the 2020 election will be whether those changes will ratify Florida’s status as a swing state and show the power of the Hispanic vote in Democratic politics or affirm the presidency of Donald Trump.

“In Puerto Rico, politics are very important for the people. It’s the number one thing people talk about,” said Santiago, a Republican who supports Trump.

In Polk County, the Hispanic registered voter population has grown from 19,000 in 2006 to 65,000 in 2018 — 15% of the total and of up from only 3% in 1980. By 2018, Hispanics made up 23% of the county’s 700,000 residents — which means the number of potential voters is likely to increase in 2020.

Traditionally, Puerto Ricans on the mainland have been considered stalwart Democrats. But as Santiago proves — and as shown by the unexpected Puerto Rican support of Rick Scott in the 2016 U.S. Senate race — such generalizations may not hold in 2020.

“That’s one of the big questions that everyone wonders about Florida: what impact will the Hispanic vote have?” said Jens Manuel Krogstad, an analyst at the Pew Research Center who studies the political engagement of Latinos in the U.S. “What is the Hispanic vote and is there a Hispanic vote? I say that because Hispanics are diverse in a lot of ways, including in their political views. Especially in Florida.”