Marco Rubio isn't a shoo-in if he were to seek re-election to the U.S. Senate, according to a new survey by the Democratic-leaning Public Policy Polling.
Rubio, a Republican, would trail Democratic front-runner Patrick Murphy 44-43 percent, the poll found. Murphy would also lead in hypothetical match-ups against Republicans Carlos Beruff (43-31 percent) and David Jolly (44-29 percent).
If Democrat Alan Grayson were the nominee instead, Rubio would be ahead 43-38 percent. Like Murphy, Grayson would do better than Beruff (41-32 percent) and Jolly (40-33 percent). The other Republicans running are Ron DeSantis, Carlos Lopez-Cantera and Todd Wilcox.
When asked if Rubio should run again, 39 percent of respondents said he should, compared to 51 percent who said he shouldn't.
Rubio has said he doesn't plan to run again, though qualifying doesn't end until June 24. He intends to fundraise that evening for Lopez-Cantera, a longtime friend.
The PPP survey also found Rubio underwater in approval ratings, with 32 percent of Florida voters giving him a thumbs-up on his job performance and 54 percent giving him a thumbs-down.
"Those numbers make him one of the least popular Senators in the country," the pollsters wrote.
As for the presidential race, PPP found a toss-up, with Republican Donald Trump ahead of Hillary Clinton 41-40 percent. Libertarian Gary Johnson garnered 4 percent support, and Green Party candidate Jill Stein drew 2 percent.
"If she can get the party unified around her after officially clinching the nomination she should have a slight edge in Florida, but for now [Bernie] Sanders supporters are showing some reluctance," according to PPP.
The firm surveyed 737 registered voters June 2-5. The poll's error margin is plus-or-minus is 3.6 percentage points.