Rep. Paul Ryan (R-Wis.) has endorsed Florida Sen. Marco Rubio's immigration plan in a Facebook post, a high-profile endorsement from a potential rival.

"Senator Rubio is exactly right on the need to fix our broken immigration system," Ryan wrote on his Facebook page. "I support the principles he’s outlined: modernization of our immigration laws; stronger security to curb illegal immigration; and respect for the rule of law in addressing the complex challenge of the undocumented population. Our future depends on an immigration system that works."