Senator Scott of Florida might be in for a tighter re-election race than previously thought, according to a new survey that shows the Democratic challenger nearly tied with the incumbent senator.

A new survey from Florida Atlantic University and Mainstreet Research found that among likely voters, Mr. Scott enjoys 45 percent support while his challenger, Congresswoman Debbie Mucarsel-Powell, had 43 percent support. Among registered voters, Mr. Scott’s lead was slightly larger, 44 percent to 40 percent.

A previous survey from the same pollster conducted in April found Mr. Scott leading Ms. Mucarsel-Powell by 16 points among registered voters and by 17 points among likely voters.

Ms. Mucarsel-Powell is a former member of Congress from South Florida. Originally from Ecuador, she lost her congressional seat in Florida’s 26th in the 2020 election.

An assistant professor of political science at Florida Atlantic University, Luzmarina Garcia, said that “Mucarsel-Powell was largely unknown in earlier surveys.”

“However, as voters have been introduced to her, she has been gaining in the race,” Ms. Garcia said. “If this trend holds, it could be close in November.”

While most handicappers still anticipate Florida leaning towards Republicans in the 2024 election, Ms. Mucarsel-Powell has focused her campaign on exploiting Mr. Scott’s unpopularity and the GOP’s stance on abortion.

“He’d strip away women’s rights with a national abortion ban,” Ms. Mucarsel-Powell said in her campaign announcement. “He cuts taxes for himself, but he’d raise them on you.”

The once perennial swing state has trended towards Republicans in recent elections. In 2022, Governor DeSantis won re-election by a large margin, benefiting many Republicans in his state electorally in a year when Republicans posted a historically weak midterm performance.

If Democrats could make the Florida Senate race competitive, it could increase their chances of retaining the Senate in 2024, a year where multiple vulnerable Democratic incumbents are up for re-election.