Sen. Marco RubioMarco Antonio RubioStudents gather outside White House after walkout to protest gun violence Overnight Energy: Senate confirms Bridenstine as NASA chief | Watchdog probes Pruitt’s use of security detail | Emails shine light on EPA science policy changes Senate confirms Trump’s pick to lead NASA MORE (R-Fla.) on Tuesday wouldn't rule out running for the White House in 2016 against his one-time political mentor, former Florida Gov. Jeb Bush (R).

Republican strategists have speculated that Rubio wouldn't want to battle against Bush in a primary, given their shared history in Florida politics.

But while Rubio said Bush would be a formidable candidate, he maintained the former governor's plans would not affect his decision about whether to seek the presidency.

“I haven't given any consideration how that would play out, but my decision would be based on me, not what anybody else decides,” Rubio said on CNN.

Rubio admitted he is eyeing a White House run, and said he would make the final call about his plan later this year or early next year. The country is at a crossroads, he said, and his decision to run will hinge on whether he can turn around the decline. 

“It is going to require us to make some changes,” he said. “If I think I can make a difference in that, from that office, to lead us in that direction, that is something I'd have to strongly consider, but that probably won't happen until later this year or early next year.”

Rubio said the front-runner for the Democratic nomination — Hillary Clinton — would be beatable in 2016. He said Clinton would have to answer for her tenure as head of the State Department and the outdated policies of the Democratic Party.

“I think a handful of people could beat her,” he said when asked whether he could win in a General Election matchup. 

“Again, she if formidable because she is experienced as a campaigner and in office. She will raise a lot of money. She may not even have a challenge in her primary. But at the end of the day, I think she is going to have a lot to answer for, and I think the American people are ready to turn the page.”

Rubio brought up the 2012 attacks in Benghazi, Libya, that resulted in the deaths of four Americans.

“Quite frankly, much of the foreign policy failures we see in place today began when she ran the Department of State," he said.

The senator touched on a number of issued during the wide-ranging interview, including immigration reform and foreign policy. 

The senator said he is not sure if immigration reform is going to happen this year, and said the lack of trust in President Obama is the largest impediment to a deal. 

He continued to advocate for a step-by-step approach to a deal, saying some of the worst legislation came out of recent comprehensive measures, including the healthcare law.