"The race is essentially unchanged from last fall, with Republicans still introducing themselves to voters and Bill NelsonClarence (Bill) William NelsonPoll: 8 in 10 people in key states concerned about driverless cars Ted Cruz and Bill Nelson give NASA a reality check on privatizing International Space Station Overnight Defense: Senate confirms Haspel as CIA chief | Trump offers Kim 'protections' if he gives up nukes | Dem amendments target Trump military parade MORE leading the field comfortably," PPP President Dean Debnam wrote in a polling memo.

Nelson's approval ratings are far from where the candidate would like to be in an election year. Thirty-six percent of Florida voters said they approve of Nelson, while 32 percent disapprove. Even among Democrats, only 55 percent approve of the senator.

One in three voters doesn't report having an opinion — a surprisingly high figure for an incumbent senator that is exaggerated further when gender is taken into account. Of the women polled, 43 percent said they didn't have an opinion of Nelson, compared to just 20 percent of men.

The poll of 700 Florida voters was conducted April 12-15 using automated telephone interviews, and had a margin of error of 3.7 percentage points.

The Hill rates this race as leaning Democratic.