@ByKristenMClark

The latest poll on Florida's U.S. Senate race by Quinnipiac University has Republican incumbent Marco Rubio with a larger lead than he did a month ago over his Democratic challenger, Patrick Murphy.

The survey of 601 likely Florida voters found 50 percent supported Rubio and 43 percent backed Murphy, a two-term congressman from Jupiter. Six percent remained undecided and 1 percent favored another candidate.

The poll, conducted Aug. 31-Sept. 7, had a margin of error of plus or minus 4 percentage points.

Another statewide poll released earlier this week by Public Policy Polling depicted a closer race in the wake of the Aug. 30 primary. It found Rubio and Murphy in a virtual toss-up -- with Rubio leading Murphy by 3 percentage points, within that poll's margin of error.

Quinnipiac's monthly poll results this summer have fluctuated drastically in terms of how large of a lead Rubio has held over Murphy, but each poll has consistently found the incumbent ahead. The university's U.S. Senate polls have shown similar swings in other states' races, too.

The university's August poll had Rubio with an edge of 3 percentage points. In July, it was 13 percentage points, and in June -- just before Rubio officially declared re-election -- Rubio had a 7-percentage-point advantage.

Photo credits: AP / Palm Beach Post