Why Jeb Bush Isn't Keeping Marco Rubio Out Of 2016 Presidential Race

— -- Newly-minted presidential candidate Sen. Marco Rubio said on Monday he won’t let his bid for the White House come between him and his long-time mentor, fellow Republican -- and likely 2016 rival – former Florida Gov. Jeb Bush.

“Jeb is my friend, he's still my friend, he will continue to be,” Rubio said in an exclusive interview with ABC News’ Chief Anchor George Stephanopoulos. “I think it’s important to understand – I'm not running against Jeb Bush, and I hope he's not running against me. We are competing for the same job.”

Rubio and Bush, who has yet to formally announce his own presidential bid but is widely expected to do so, have been close friends for more than 15 years. When Rubio was contemplating his first Senate run, he pledged to defer to Bush if the governor wanted the seat. So many pundits assumed Rubio would bow out of the 2016 contest if Bush launched a bid.

Not so.

“It's a different time,” Rubio said in the interview that took place at his West Miami home. “Back then, I was the termed-out Speaker of the Florida House, he was the former sitting governor of Florida. I was at different time in my life and in my career, and the country was at a different moment.”

“I just feel uniquely called to at least lend my voice to this effort – and I think we're going to be successful,” the Florida senator told Stephanopoulos. “My view of the primary is we are all going to go out and make our best argument and the voters are going to decide who they want.”

Rubio, 43, revealed in 2012 that his motto in the Senate was WWJD – “What would Jeb do?.”

Rubio said he still has “tremendous admiration” for the 62-year-old former Florida governor. But the country needs a “new and vibrant” candidate, he said.

“I think that Jeb Bush continues to be a model for people in terms of how you approach public policy. I believe public policy should always be about policies and big ideas,” Rubio said on Monday. “But we've reached a moment now, not just in my career, but the history of our country, where I believe that it needs a Republican Party that is new and vibrant, that understands the future, has an agenda for that future, and I feel uniquely qualified to offer that. And that's why I'm running for president.”