In a new poll, two-term Sen. Bill Nelson led likely GOP nominee Rep. Connie Mack IV by 4 points in a Florida Senate matchup.

Nelson topped Mack 43 percent to 39 percent in the poll of registered — not likely — Florida voters. Nelson led among independent voters by 11 points, 44 percent to 33 percent.

Forty-four percent of those surveyed had a favorable opinion of Nelson and 26 percent had an unfavorable opinion of him.

Thirty-four percent of those surveyed had a favorable opinion of Mack and 22 percent had an unfavorable opinion of him. Forty-two percent of those polled said they didn’t know enough about the four-term Congressman to form an opinion.

Mack’s top primary opponent, former Sen. George LeMieux (R-Fla.), dropped out of the race Wednesday, but the Congressman still has a steep hill to climb in unseating Nelson, top GOP and Democratic operatives in the state told Roll Call.

The Quinnipiac University poll surveyed 1,697 registered Florida voters from June 12-18. Live interviewers called respondents on landlines and cellphones. The margin of error was 2.4 points.