The U.S. Senate matchups show:

Florida – Sen. Marco Rubio over U.S. Rep. Patrick Murphy 50 – 37 percent, and Rubio leading U.S. Rep. Alan Grayson, another possible Democratic challenger 50 – 38 percent;

Ohio – Sen. Rob Portman over former Gov. Ted Strickland 47 – 40 percent;

Pennsylvania – Sen. Pat Toomey over Democrat Katie McGinty 49 – 39 percent.

“The numbers seem to be breaking the Republican way in the battle for control of the U.S. Senate, at least when it comes to the critical swing states of Florida, Ohio and Pennsylvania,” said Peter A. Brown, assistant director of the Quinnipiac University Poll.