So if you're one of the many people who had never heard of McMullin until now, here are six things you should know about him.
He has been very critical of Donald Trump
Check the tweets:
He is from Utah and went to Brigham Young University
McMullin's ties to Utah are significant because if he is going to be competitive anywhere, it could be in a red state where Trump is leading, but not very popular. Recall that the Republican presidential nominee finished third in Utah's GOP caucus in March — some 55 points behind winner Ted Cruz. Libertarian Gary Johnson is polling at 16 percent there right now.
In short, the people of Utah might go for a non-Trump conservative.
McMullin already has missed deadlines to appear on ballots in 26 states, making his odds even longer than they might seem (if such a thing is possible). But if his mission is to stop Trump, snagging six electoral votes in Utah could make a difference in a tight election.
He was in the CIA
McMullin led counterterrorism and intelligence operations in the Middle East, North Africa and South Asia, according to his campaign bio. He will undoubtedly use his background to claim superior knowledge of global affairs and strike a contrast with Trump, who is new to foreign policy yet has boasted, "I know more about ISIS than the generals do."
After leaving the CIA, McMullin worked in the investment banking division of Goldman Sachs, where he says he learned about a range of business sectors, including technology, real estate and energy.
Before launching his campaign, he was chief policy director of the House Republican Conference
On LinkedIn, McMullin described his job as managing "the development and advancement of House Republican Conference domestic and foreign policy initiatives." He added that "specific areas of focus have been foreign affairs, national security, technology, health care, finance, government reform, natural resources and women's empowerment."
In a press release announcing his appointment to the post in January 2015, the GOP conference said that "in 2012, Evan assisted Republican nominee Mitt Romney's presidential campaign in the Western region." In between, he was a senior adviser to House Foreign Affairs Committee chairman Rep. Ed Royce (R-Calif.)
His TEDx talk about preventing genocide has been viewed about 2,000 times
That's not very many, by YouTube standards, but he appears to be a solid public speaker.
He already has a super PAC behind him
To be even remotely relevant, McMullin will need money. And, as The Washington Post's Matea Gold reported, he already has the backing of two Republican strategists with experience in third-party ballot access.
Kahlil Byrd, who served as chief executive of Americans Elect, a now-shuttered organization that sought to create a pathway for an independent presidential candidate in 2012, and Chris Ashby, a GOP campaign finance attorney who worked on that effort, are together launching a new super PAC called Stand Up America to support McMullin."We want to be the conduit for people to be able to stand up and not just support his candidacy, but the efforts of an independent to satisfy the American people’s need for something more than they have seen," Byrd told The Washington Post. "We are down to the two major party candidates, yet people are still looking for someone else."