The favorite for the 2016 Democratic nomination is viewed more favorably than either Republican, posting a 62-33 favorable edge over Bush and a 41-34 split over Rubio.
“We probably won't know for some time whether former Secretary of State Hillary Clinton runs for president in 2016, but if she decides to make the race, she begins with a sizable lead in a state that Republicans cannot win the White House without,” said assistant director of the Quinnipiac University Polling Institute Peter A. Brown in a statement announcing the polling results.
"Florida voters have a very positive view of Mrs. Clinton, and it's not just Democrats who feel that way," he added.
Clinton is viewed favorably by 26 percent of Republicans and by independents at 57 to 35 percent. She also posts a 10-point gender gap, with 66 percent favorability among female voters to 56 percent among men.
Rubio has not said he is considering a 2016 run, but visited Iowa late last year and has maintained a high profile, taking a lead role in Senate negotiations over immigration reform and delivering the GOP response to President Obama’s State of the Union.
Bush earlier this month said he had not ruled out a 2016 bid and would consider the matter.
“I have a voice and I want to share my beliefs about how the conservative movement and the Republican Party can regain its footing,” he said.