This Politico story analyzes election law in Kentucky and Florida and concludes that neither Rand Paul nor Marco Rubio can simultaneously run for the Republican presidential nomination, and for re-election to the U.S. Senate, in 2016. Thanks to Gene Berkman for the link.
The article does not provide a link or text of the law, but the voters of Kentucky and Florida vote for members of the Electoral College, not for the nominees of any political party or for independent candidates. The candidate names are there for convenience.
However, the article jumped between the primary and general election, so it is unclear whether the laws apply on a primary ballot.
Both states have presidential primaries, and I think the article was mostly focused on them. The article does mention the possibility that Rand Paul would skip the Republican presidential primary in his home state, but that would be harmful to his campaign.
Could Rand not place a surrogate on the presidential ballot — someone who after winning the primary could release his delegates? Since the Republican Party made a rule that the Presidential candidate chooses the delegates, the surrogate could choose people who would definitely cast their votes for Paul.
Since I’m not planning on running for anything in 2016, I’d be willing to do it, although Mrs. Paul would be a better choice if she is willing.
#1 Florida Statute 99.012 precludes running for two offices at the same time.
It does have an exception for federal offices, including President and Vice President, but that is to the resign-to-run law.
In Florida, a candidate may not run for another office in the middle of their term, without resigning their office, without the only exception being federal offices.