Marco Rubio has news for anyone who thinks Democrats have 2016 in the bag: Hillary Clinton could lose.
The junior Republican senator from Florida made his opinion of the former first lady known Friday on Hugh Hewitt's radio show, saying, "Multiple people can beat her. Hillary Clinton is not unbeatable."
Rubio slammed Clinton's record on foreign policy, saying, "I'd ask her, 'You were the secretary of state during the first four years of the Obama administration. Name one significant foreign policy achievement, now or after you left?'"
While Clinton has admitted to considering a potential 2016 run, she has yet to officially announce her candidacy. Nonetheless, Clinton is widely considered the Democratic front-runner for president.
Rubio recently made headlines over his views on man-made climate change. He told ABC News' Jon Karl in May that he doesn't believe humans are contributing to the earth's rising temperatures.
“I do not believe that human activity is causing these dramatic changes to our climate the way these scientists are portraying it,” Rubio said.
Rubio's views have drawn harsh words back home. South Miami Mayor Philip Stoddard called the senator an "idiot" over his position on climate change.
"He says he is not a scientist," Stoddard told The Guardian in an article published Friday, "so he doesn't have a view about climate change and sea-level rise and so won't do anything about it."
Rubio's office did not respond to msnbc's request for comment.