Marco Rubio has scored yet another endorsement from a wealthy Republican donor in support of his 2016 presidential bid.

After observing all of the GOP candidates, Oklahoma City-based energy executive Larry Nichols decided that Rubio was the best contender to bring the nation together.

"As I have witnessed all of the candidates during past several months, during debates, speeches and interviews; I think that Marco Rubio is the candidate that's most likely to be able unite this fractured country and move the United States forward," said the chairman of Devon Energy, one of the largest independent natural gas and oil producers in the U.S., during an interview with The Hill on Sunday.

Nichols said he made his decision within the last week, when the Florida senator won him over with his "reasoned judgment" on policy issues, reports NBC News.

"I like his vision for America. I think he's the best candidate to bring the party together," he said.

Although Nichols has already made the maximum personal contribution to Rubio's campaign, he says he will "consider any ways that I might help [Rubio] in the future." One way he planed to help was by encouraging people in his network to become supporters of Rubio's 2016 bid.

Throughout his career, Nichols has made over $800,000 in political contributions. The longtime GOP donor also contributed more than $350,000 in the 2014 election cycle alone.

Nichols is the latest person to join the list of high-profile donors to throw their weight behind the congressman. Earlier this month, Ken Griffin, a billionaire hedge fund manager who is considered to be the wealthiest person in Illinois, announced that he is backing Rubio's campaign.

"I'm really excited to be supporting Marco Rubio. He will be the next president of the United States," said the founder of the Chicago-based firm Citadel, during an interview with CNBC.

Rubio also secured donations from hedge fund billionaire Paul Singer, billionaire Florida car magnate Norman Braman and influential North Carolina businessman Art Pope.