Republican presidential candidate Marco RubioMarco Antonio RubioHillicon Valley: Amazon wins union election — says 'our employees made the choice' Overnight Defense: Biden proposes 3B defense budget | Criticism comes in from left and right | Pentagon moves toward new screening for extremists The growing threat of China's lawfare MORE lost his voice on Monday ahead of a campaign event.

Rubio was introduced by South Carolina Gov. Nikki Haley, who endorsed him earlier this month, at the event. Haley told the crowd that Rubio had lost his voice. 

ADVERTISEMENT

Rubio proceeded to speak with a hoarse voice after Haley's introduction.

An an earlier event in Tennessee, Rubio vowed to sacrifice his voice for the future of the country and to beat rival Donald TrumpDonald TrumpHarry Reid reacts to Boehner book excerpt: 'We didn't mince words' Man arrested for allegedly threatening to stab undercover Asian officer in NYC Trump says GOP will take White House in 2024 in prepared speech MORE.

“We’ve been working hard for you,” he said, according to Breitbart News.

“And if it means by the end of tonight, I don’t have a voice and I have to whisper how strongly I feel about the future of this country, then I’m willing to do it.

“Our Veterans and so many others have given up way much more than just their voice for just one day,” he added.
 
Rubio and Trump have engaged in personal attacks in recent days, mocking each others appearance and background.