One of Donald Trump's earliest supporters in Congress is forcefully pushing back against political leaders and pundits who have sought to convince voters that the Republican nominee is not presidential material.

In late February, Rep. Duncan Hunter, R-Calif., became the second congressional Republican to endorse Trump. He has since defended Trump at every turn, from his ethnically-driven attack on a federal judge to his latest claim that President Obama is the "founder of ISIS."

Now, as Trump's behavior and untamable tongue continue to raise questions about whether he is qualified to hold the highest office in the land, Hunter has found himself once more defending the GOP presidential nominee.

"For Donald Trump, the latest recurring question around his candidacy — incited by the liberal left and parroted by even some Republicans — is whether he has the right temperament to be Commander in Chief," the California congressman wrote in a lengthy op-ed for Politico.

"What is so hard for Trump's detractors to grasp is that what they don't like about Donald Trump has nothing to do with temperament — he's got it," Hunter claimed, adding that Trump has "proved over the course of his highly successful business career that he's got all the right qualities as a leader and a visionary."

Hunter believes those questioning Trump fitness to serve as commander in chief have "purposefully" conflated his temperament with his style because "they're not used to it [and] they can't process it."

"Trump's comments regarding the Islamic State, underscoring the President's failed foreign policy is proof," Hunter claimed. "So the immediate reaction is to describe this comment, no different than others, as reckless and as an indictment on Trump's temperament. It's not."

While Trump's unrefined speaking style and "abandonment of political correctness" has offended "the political and academic elite" and led them to attack his temperament, Hunter said the billionaire simultaneously "speaks to the heart and soul of hard working Americans in a way they comprehend."

"Those launching the attacks, to include some Republicans, really just take issue with [Trump] personally," he suggested. "Why not be truthful and say, 'I just don't like the guy.'"

Trump himself has dismissed those who say he lacks the character and level-headedness to be president, claiming that his Democratic opponent is the one who should be more carefully examined. At a rally on Wednesday, he described Clinton as having "the temperament of a loser."

"I don't like her temperament," he told supporters in Fort Lauderdale, Fla. "I don't like her temperament because she's weak. We need somebody who knows how to win."