An online poll in Florida's U.S. Senate race again underscores a close contest in the nation's biggest battleground state.

The Axios/SurveyMonkey poll has Republican Gov. Rick Scott with a 3-point edge over Democratic Sen. Bill Nelson, 49-46 percent, with 5 percent giving no answer. The pollster surveyed 1,080 voters from June 11 to July 2, with a margin of error of 5 percentage points.

Asked to name an issue that matters most, 23 percent in Florida said jobs and the economy — Scott's signature issue. Health care followed at 19 percent, with immigration third at 18 percent.

Floridians are closely divided in the poll on President Donald Trump's performance: 50 percent approve, 49 percent disapprove.

They were equally split on Nelson's performance, with 47 percent registering approval and 47 percent disapproval. Six percent had no opinion.

Republican Sen. Marco Rubio got a slightly better approval grade of 52 percent with 47 percent disapproval.

Nelson is one of three red-state Democratic senators trailing Republican challengers in the poll. The others are Joe Donnelly in Indiana and Heidi Heitkamp in North Dakota.

Axios said respondents were selected from the nearly 3 million people who take surveys on the SurveyMonkey platform daily.