The line-up of this year's Conservative Political Action Conference could be an indicator of which Republicans are preparing for a White House run in 2016.
The American Conservative Union announced Thursday that Florida Senator Marco Rubio has been added to the speaker list for the conference.
The CPAC is the largest gathering of conservative leaders and activists, and it has launched the presidential campaigns of many Republican candidates.
It will be held March 14-16 at the Gaylord National Resort and Convention Center just outside Washington.
Congressman Paul Ryan, Senator Rand Paul and former Senator Rick Santorum are also scheduled to speak at the event.