MIAMI (CBSMiami/AP) – Florida Senator Bill Nelson and GOP challenger Connie Mack IV have both sailed to easy wins in their primary races.

A Republican U.S. Senate showdown is one of the highlights on the ballot.

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Rep. Mack easily defeated former Congressman Dave Weldon and tea party favorite Mike McCalister in the GOP Senate race.

Mack’s father, Connie Mack III, is a former senator and his great-grandfather was a Hall of Fame baseball manager and he has benefited from a better-financed campaign.

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Mack has already been acting as if his nomination is a foregone conclusion and is gearing up for a November matchup with Democratic Sen. Bill Nelson, who faced minor primary opposition in his bid for a third term.

Mack entered the race in November and was immediately considered the front-runner, jumping to a lead in the polls far ahead of a crowded field that was struggling for traction. Weldon didn’t join the race until three months ago, saying that conservatives lacked enthusiasm for Mack. Retired Army Col. Mike McCalister is also in the race, but his campaign has not gained traction after an initial boost from tea party activists.

In June, former Sen. George LeMieux dropped out of the race, in part because Mack refused to debate him and other primary candidates. LeMieux said he didn’t have enough money to show a contrast with Mack. LeMieux was appointed by then-Gov. Charlie Crist to fill the last 16 months of Sen. Mel Martinez term.

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Senate President Mike Haridopolos was also briefly in the race before dropping out, as were former state Rep. Adam Hasner and former Ruth’s Chris Steak House CEO Craig Miller, who are now seeking U.S. House seats.