Pluralities of all registered voters have favorable opinions of both Nelson and Mack, but significant percentages say they do not know enough about each candidate to form an opinion, even of Nelson, a two-term Senator, former statewide officeholder and one-time astronaut-Congressman. Forty-one percent of voters have a favorable opinion of Nelson, compared to 23 percent who view him unfavorably. But 35 percent say they haven't heard enough about him to have an opinion. Mack's favorable-unfavorable spread is also nearly positive-20 points, as well: 32 percent of voters have a favorable opinion of Mack, whose father held the Senate seat Nelson currently occupies, and 13 percent have an unfavorable opinion. A majority, 54 percent, say they haven't heard enough about him. But Nelson could his fortunes tied to those of his party's standard-bearer, President Obama. According to the poll, a majority of Florida voters don't think Obama deserves reelection, and the president narrowly trails GOP frontrunner Mitt Romney by three points. The Quinnipiac poll was conducted Jan. 4-8, surveying 1,412 registered voters.