Democratic-leaning PPP poll finds U.S. Sen. Bill Nelson beating Republican front-runner Connie Mack by 11 points, 46-35.

"Several Florida Senate polls conducted shortly after Connie Mack IV's entry into the race found a toss up contest, but PPP's newest look finds that any announcement bump Mack may have received has now receded," the poll states. "In March we found Nelson with a 13 point advantage and last December we found him ahead by 9 points."

It goes on: "Nelson has two big things going for him in a match against Mack. One is that he wins 14% of the Republican vote, an unusual amount of crossover support for a Democrat. The other is that he has a 42/33 advantage with independent voters. 22% of Republicans are undecided compared to only 13% of Democrats so this race will likely tighten up once the GOP unites around a candidate, but for now Nelson has a healthy lead."

The conclusion: "It's going to have to be a pretty bad year for Democrats nationally in order for Nelson to be defeated."

Read the analysis here.