Sen. Bill Nelson, D-Fla., holds a significant lead and has cracked the critical 50-percent threshold over Republican Rep. Connie Mack, according to a poll released Thursday by Quinnipiac University/CBS News/New York Times.
Conducted in the days immediately following Mack's victory in the GOP primary, the poll shows Nelson leading the Republican, 50 percent to 41 percent. In the previous poll, conducted last month, Nelson led Mack, 47 percent to 40 percent.
Nelson outperforms the top of the Democratic ticket in the poll: President Obama is locked in a statistical tie with Mitt Romney.
Mack easily won a crowded Republican primary last week. None of his GOP opponents ran any television ads, and Mack declined invitations to participate in pre-primary debates, allowing him to escape the primary relatively unscathed. But Nelson released a television spot at the beginning of the month attacking Mack.
The senator has a huge fundraising advantage over his opponent, but GOP outside groups have pledged to spend millions on Mack's behalf.
The Quinnipiac University/CBS News/New York Times poll of 1,241 likely Florida voters was conducted August 15 through August 21. The poll has a margin of error of plus-or-minus 2.8 percentage points.