Florida Senator Marco Rubio launched his bid for the Republican presidential nomination race on Monday (April 13). The conservative 43-year-old first-term lawmaker is the third Republican hopeful to formally announce a White House bid, following declarations by Senators Ted Cruz of Texas and Rand Paul of Kentucky.
Here are 10 things to know about Mr Rubio.
1. Rise to politics
Mr Rubio was first elected to the Senate in 2010, riding on a conservative Tea Party wave that sent several small-government conservatives to Congress. As an underdog, he took on former Florida governor Charlie Crist in what was seen as an upset victory.
2. Son of Cuban immigrants
He is the son of poor Cuban immigrants. His father worked as a bartender and his mother as a maid and cashier. He is bilingual in English and Spanish and made much of his immigrant roots at his campaign announcement. In fact, the announcement was made at a rally at Miami's Freedom Tower, where thousands of Cuban exiles fleeing the Communist-run island in the 1960s were first registered by US authorities. Should he win in 2016, he would make history as the nation's first Hispanic commander-in-chief. He has also previously come under fire from his own party for supporting an immigration reform bill that would have legalised millions of undocumented migrants.
3. Challenger to Jeb Bush
Mr Rubio is seen by analysts as a key opponent to former Florida governor Jeb Bush, who has not yet declared himself a candidate but is widely expected to do so. Mr Rubio's decision to forgo a run for re-election to the US Senate and to compete against Mr Bush for the presidency has been the talk of the town in Florida. Mr Bush was a big supporter of Mr Rubio when he was the Florida governor and Mr Rubio was the speaker of the Florida House of Representatives. Aides to both men say there has been no bad blood between them, and both are willing to compete against each other to seize the presidency.
4. Campaigning on youth, diversity
His campaign aims to tout his ability to appeal to the young, Hispanic and African-American voters that Republicans have struggled to reach in previous elections. The announcement focused on how to help middle-class Americans through an optimistic message of upward mobility and economic solutions geared to the 21st century.
5. Foreign policy edge
Hawkish on foreign policy, Mr Rubio hopes to stand out by touting his credentials for international affairs. He is a member of the Senate Foreign Affairs and Intelligence committees and will seek to underscore his knowledge and engagement on international issues on the campaign trail. As an example of this, Mr Rubio has chosen to forgo the customary post-announcement campaign swing to fly back to Washington to attend a Committee meeting on legislation that would allow Congress to approve any nuclear deal reached with Iran.
6. His Water-gate moment
Perhaps his most memorable moment came during the GOP rebuttal to Mr Obama's State of the Union in 2013. Looking parched in the middle of his speech on foreign policy and the economy, he took an uncomfortable pause as he quickly gulped down a drink from his water bottle while struggling to make eye contact with the camera. That moment has since become the subject of many memes and countless tweets poking fun of him.
7. Family life
Mr Rubio lives with his wife, Jeanette, in West Miami and the couple have four children - Amanda, Daniella, Anthony and Dominic. The two have been married since 1998.
8. Loves American football and hip hop
Outside of politics, he is known for his passion for American football and had even dreamed of a professional career. He is a die-hard Miami Dolphins fan and his wife appears to be a fan too, having once been a cheerleader for the team. He is also a fan of hip hop and counts rapper Tupac as among his musical guilty pleasures.
9. A former Mormon
Mr Rubio was previously a Mormon, having been baptised at age 8. He and his family returned to the Roman Catholic Church several years later.
10. Law degree
Mr Rubio earned his law degree from the University of Miami. He also teaches classes in politics at Florida International University (FIU). USA Today cited his teaching partner and political science professor Dario Moreno at FIU as saying that Mr Rubio "thinks out loud in the classroom" about policies facing him both as a senator and potential presidential candidate.
SOURCES: REUTERS, AGENCE FRANCE-PRESSE, NEW YORK TIMES, USA TODAY, POLITICO, BIOGRAPHY.COM