In a three-way contest, according to a new Rasmussen poll:

The new poll shows Rubio with 37%, Crist with 30% and Meek with 22% in a three-way matchup. The margin of error is 4.5.
The new Rasmussen numbers shows that Crist is actually gaining ground on Rubio as an independent. A March Rasmussen poll of a three-way Florida Senate race showed an independent Crist running third amongst the three candidates, and 17 points behind Rubio as the Republican nominee.
Crist hasn’t seen his poll numbers move in that direction against Rubio for quite a while.