House Speaker John Boehner, R-Ohio, and Senate Republican leader Mitch McConnell, R-Ky., announced the selection of Rubio on Wednesday, calling him a strong advocate of conservative principles.
Rubio will speak after Obama's prime-time address before Congress, offering a counterweight to the president's agenda. The high-profile speech gives Rubio a broad national audience for a party that lacks a true standard-bearer after Obama's re-election.
Boehner called Rubio "one of our party's most dynamic and inspiring leaders. He carries our party's banner of freedom, opportunity and prosperity in a way few others can."
McConnell said his Senate colleague would "contrast the Republican approach to the challenges we face with President Obama's vision of an ever-bigger government and the higher taxes that would be needed to pay for it."
The 41-year-old Cuban-American lawmaker was given a prominent speaking role at last year's Republican National Convention and traveled extensively on behalf of Republican presidential candidate Mitt Romney. He has been touted as a potential presidential candidate in 2016 for a party that fared poorly among Latino voters last year. In a signal of renewed outreach to Hispanic voters, Rubio's address will be delivered in both English and Spanish.
Rubio has played a leading role among Republicans in seeking changes on immigration, one of the top legislative priorities of the year for both parties. He has been part of a bipartisan group of senators who have proposed a plan that would allow illegal immigrants to pursue citizenship after a number of steps are taken to secure the border with Mexico. The issue is expected to be among the most highly-watched measures in Congress this year.
On the economy, Rubio has said tax increases will not bring down the nation's $16 trillion debt and urged policies to promote economic growth and changes to entitlement programs.
Rubio said he would discuss "how limited government and free enterprise have helped make my family's dreams come true in America." He said the speech would help lay out "the Republican case of how our ideas can help people close the gap between their dreams and the opportunities to realize them."
Rubio, a former state house speaker from Miami, became a popular figure among tea party activists during his improbable rise during his 2010 Senate campaign. He defeated Florida Gov. Charlie Crist, who switched to run as an independent when it became clear he would lose the Republican primary to Rubio.
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