Washington(CNN) Florida Sen. Marco Rubio is on track to run for President in 2016 even if Jeb Bush also jumps into the race, a source close to Rubio says.
The source told CNN that a Bush candidacy -- increasingly likely after the former Florida governor said in a Facebook post Tuesday that he will "actively explore" running -- changes the dynamics of the race "but not Marco's thought process."
Rubio has invited supporters to a Jan. 23-24 retreat in Miami Beach, where his top aides and donors could formalize his plans for 2016.
A run for president would be a big risk for Rubio, a 43-year-old former Florida House speaker who looks like a sure bet to win a second term in the Senate in 2016.
He's making the moves of a presidential contender. Rubio campaigned with GOP candidates in the 2014 midterm election. He has a memoir set for release in January. And he's working with incoming House Ways and Means Chairman Paul Ryan (R-Wis.) to craft health care legislation meant to be an alternative to Obamacare.
He's also been increasingly vocal on foreign policy issues -- potentially setting up a clash with leading Republican contenders like Kentucky Sen. Rand Paul, who has called for less U.S. intervention overseas.
Rubio, though, would share one problem with Bush: He's championed an overhaul of U.S. immigration laws, a position that has fallen out of favor with much of the GOP base.