Republican Marco Rubio is the junior U.S. Senator from Florida, a seat he has held since 2011. Prior to holding national office, he served as speaker in the Florida House of Representatives from 2007-2009. Rubio is the son of Cuban immigrants and a native of Miami. He attended the University of Miami School of Law.
Rubio announced his candidacy for the 2016 presidential race on April 13th, 2015. (You can watch video of his announcement speech below.)
Further reading/viewing:
Video: Senator Marco Rubio's full presidential announcement speech, via C-SPAN)