TALLAHASSEE, Fla. (AP) -- President Barack Obama holds a small lead over Republican challenger Mitt Romney among Florida voters in a new poll.

A Quinnipiac University random telephone survey of 1,697 registered voters in the nation's largest swing state shows the president favored by 46 percent of the respondents compared to Romney's 42 percent. The poll has a margin of error of plus or minus 2.4 percentage points.

Romney led in a similar Quinnipiac survey last month when he was preferred by 47 percent to Obama's 41 percent.

The poll also shows U.S. Rep. Connie Mack headed for a victory in the Aug. 14 Republican primary and a shot at unseating two-term Democratic U.S. Sen. Bill Nelson. The poll showed Nelson with a 43-39 advantage over Mack if the general election were now.