The poll has U.S. Rep. David Jolly leading handily in the Republican primary over Florida Lieutenant Governor Carlos Lopez-Cantera.
But 55 percent of G.O.P. voters are still undecided, and pundits widely believe that former Florida Attorney General Bill McCollum would soar to the top spot if he gets into the race.
On the Democratic side, U.S. Congressmen Alan Grayson and Patrick Murphy are statistically tied in their primary, but 35 percent of voters are undecided.
The telephone poll was done from July 20 to July 25 and the margin of error is 4.5 percent.