The Florida Republican was reacting to comments from Los Angeles Mayor Antonio Villaraigosa, who said the array of Hispanic speakers at the GOP convention isn't enough for Mitt Romney to woo Latino voters.
Rubio, who will formally introduce Romney before he accepts the GOP presidential nomination, says Republicans can't just be the anti-illegal immigration party, they have to be the "pro legal immigration party."
He tells ABC's "Good Morning America" there are problems with Obama's decision to stop deporting younger illegal immigrants who came to the U.S. as children. Romney has promised to change that strategy but has not specified how.
Polls have shown Romney struggling to gain traction with Latino voters.