Rubio lost to Trump in 2016 but he’s living his best life as Secretary of State, approved unanimously by his Senate colleagues.

Marco Rubio has been confirmed by the Senate for secretary of state with unanimous support. Now comes the hard part that could make or break his tenure: retaining the full backing of his new boss, Donald Trump.

Follow the latest Marco Rubio news stories and headlines. Get breaking news alerts when you download the ABC News App and subscribe to Marco Rubio notifications.

The Senate confirmed Senator Marco Rubio, Republican of Florida, on Monday as America’s 72nd secretary of state, putting a former political rival of President Trump at the helm of American diplomacy.

Washington — The Senate on Monday confirmed Marco Rubio as secretary of state, making him the first of President Trump's Cabinet nominees to win the approval of the upper chamber. The Senate confirmed Rubio in a 99 to 0 vote as his former colleagues in the Senate touted his qualifications for the job.

The Senate has confirmed Marco Rubio as secretary of state, giving President Donald Trump the first member of his Cabinet

Rubio called China the "most potent, dangerous adversary" during his confirmation and is expected to work with India, Japan, and Australia to counter this.

The Senate voted on Monday to confirm Marco Rubio as President Donald Trump’s secretary of state, the first high-level Cabinet official for the new administration to be approved by the chamber.

He was also a candidate in the 2016 GOP presidential primary race, where Trump dubbed him "Little Marco" and Rubio warned voters not to support Trump, saying "friends do not let friends vote for ...

Sen. Marco Rubio, R-Fla., is widely expected to have one of the smoothest confirmation hearings among President-elect Trump’s Cabinet picks on Wednesday. Yet in a reasonable world, his record of ...

Congratulations, Marco Rubio! You’ll soon be secretary of State. Condolences, too. You’re not likely to last long in the job. Unlike many of President-elect Donald Trump’s nominees ...

WASHINGTON – Last time Donald Trump won office, it was Sen. Marco Rubio asking the probing questions. The Florida Republican used his perch on the Senate foreign affairs panel to grill Trump ...