ORLANDO, Fla. — Marco Rubio has maintained his lead over Val Demings in Florida’s U.S. Senate race, a poll released Tuesday finds. The Mason-Dixon Polling & Strategy survey showed Republican U.S. Sen. Rubio with 47% of the vote and Democratic U.S. Rep. Val Demings with 41%. Another 10% were undecided. The margin of error in the poll is 3.5%. The survey was taken of registered and likely Florida voters from Sept. 26 to 28. “Despite millions of dollars spent on advertising by both campaigns, little seems to have changed since February when Rubio led 49%-42%,” wrote Mason-Dixon director Brad Coke…