Evan McMullin announced his campaign as an independent presidential candidate Monday morning. He wasted little time before delivering the harshest attacks Republican nominee Donald Trump has been hit with from a rival.

After resigning from his post in the House Republican Conference and stealing the Monday news cycle, McMullin went on ABC's World News, where he escalated his criticism of Trump to a new level, saying the billionaire businessman's comments about Khizr Khan's son indicates "he is inhuman."

"I think he's a political opportunist. I think he's always been an opportunist. I think he's in it for himself. He's always been in it for himself," McMullin said. "That's his legacy. That's his track record. That's his brand."

The former CIA agent said Trump's idea to temporarily halt refugees from countries dominated by the Islamic State was an example of how he would lead like an authoritarian and "co-optee" of Russian President Vladimir Putin.

"Donald Trump is an authoritarian and the leaders around the world that he admires and aspires to be are all authoritarians. He speaks openly about it. I think we all need to be concerned," McMullin said. "I do believe he is a fraud and a con man and that's not something I say lightly. I think he doesn't care about anyone but himself."

But the tone he took dissing Trump, sounded ironically similar to the type of digs the GOP leader has uttered against his enemies. For example, he said Trump doesn't have much energy, which is similar to one of Trump's constant digs at Clinton.

"Look, Donald Trump is defeating himself. He is ensuring that Hillary Clinton is elected," McMullin explained. "It's clear to me that he is a weak candidate. Trump is weak and, in fact, I question whether he has the stamina to complete the race."

The 40-year-old candidate said he and Democratic nominee Hillary Clinton both are "woefully unfit for the responsibilities they seek," which prompted him to enter the race so late in the election season. McMullin added his campaign is not meant to block Trump from winning and help Clinton. Instead, he said he is totally motivated to win the Oval Office come November even though he will not be featured as a candidate on ballots in 27 states.