But there are some indications that a non-political candidate may be on Trump's radar: Trump has asked about Lt. Gen. Michael Flynn in the context of his search for a vice president, a source familiar with the conversation told CNN.
When asked about the possibility of serving as Trump's running mate, Flynn's chief of staff didn't dismiss the idea.
"We are not going to comment at this time. Let's let the process play itself out," said Michael G. Flynn, the general's son and top aide, told CNN.
Flynn might seem an unlikely choice given his lack of political experience -- and the fact that he's a registered Democrat.
"If someone were to look it up right now, I'm a registered Democrat, and I'm OK with that," he told Foreign Policy
, adding, he is "about as centrist as possible."
But Trump has promised to "knock out ISIS" and Flynn boasts an impressive military resume. The presumptive Republican nominee told Fox News' Greta Van Susteren in May that he had one person in mind for the job who is "not government-related as much" but who would "fit the role very nicely."
If Trump were to go this route and decide he wanted an out-of-the-box pick, Flynn would fit the bill.
So, with the potential to play spoiler in a politician-heavy VP field, who exactly is Lt. General Michael Flynn?
In 1981 Flynn was commissioned in the U.S. Army as a second lieutenant in Military Intelligence and assigned as a paratrooper to the 82nd Airborne Division at Fort Bragg, North Carolina. Flynn is a graduate of the University of Rhode Island, has an MBA, and a degree from the U.S. Naval War College.
Flynn has held a number of military intelligence leadership posts, including commander of a military intelligence battalion in Afghanistan, director of Intelligence for United States Central Command, which oversees all U.S. military operations in the Middle East, and director of Intelligence for the Joint Staff.
Most recently, Flynn was the head of the Defense Intelligence Agency before he was forced out after facing "pressure from Director of National Intelligence James R. Clapper Jr. and others in recent months," according to The Washington Post. The Military Times
reported that he was "forced out of his role after sparring with Obama advisers on a range of policy decisions.
"I was asked to step down," Flynn told Foreign Policy
. "It wasn't necessarily the timing that I wanted, but I understand."
After leaving the DIA, Flynn became a harsh critic of the Obama administration's military and foreign policy, as well as a frequent commentator on the 2016 race.
Flynn told Al-Jazeera
that he thought the Obama administration's drone policy was a failed strategy and told CNN that the White House ignored reports prefacing the rise of ISIS in 2011 and 2012 because they did not fit its re-election "narrative."
In an interview with the German publication Der Spiegel,
Flynn said that removing Saddam Hussein in Iraq and Moammar Gadhafi in Libya helped destabilize the region.
He also told CNN's Jake Tapper that he thought Hillary Clinton should withdraw from the presidential race while the FBI investigate her use of a private email server for official government communication while secretary of state.
"If it were me, I would have been out the door and probably in jail." Flynn said, adding that Clinton demonstrated a "lack of accountability, frankly, in a person who should have been much more responsible in her actions as the secretary of state of the United States of America."
When pressed by Tapper, however, Flynn said, "I don't have any personal evidence" of any wrongdoing on behalf of Clinton.
Flynn told CNN in February that he has been advising Trump "on a range of issues," such as national security and foreign policy. Flynn has taken to Twitter to re-tweet Trump often, including key Trump foreign policy points such as "In trade, military and EVERYTHING else, it will be AMERICA FIRST! This will quickly lead to our ultimate goal: MAKE AMERICA GREAT AGAIN!"
Speaking with Al-Jazeera English
, however, Flynn said that he "doesn't agree with everything Donald Trump has said," expressing hesitation about some of Trump's more controversial foreign policy statements such as bringing back waterboarding and "taking out" terrorists families.
"There must be more precision in the use of the language that he uses as the potential leader of the free world," Flynn said, adding that is the "advice that I'm trying to get into him."