Donald Trump said Sunday that the Republican Party isn't treating him well, suggesting he could go back on his pledge to support the eventual Republican nominee in the 2016 White House race if the party establishment keeps trying to take him down.

"I've been very good, I've been very straight and honest and honorable and they're not treating me right," he said on CBS' "Face the Nation." "You look at the way they stake the audiences in the debates ... they have this lightweight Senator Marco Rubio saying terrible things, just personal, terrible things."

He didn't say outright that he would break the GOP loyalty pledge, but added that he doesn't feel the Republican Party has held up its end of the bargain--and that he wanted to remind them that he represents "millions of people" who have voted for him thus far.

"I signed a pledge and I will, you know, abide by the pledge unless they default, but as far as I'm concerned they're defaulting," he said.

As for his tax returns, which have become an issue in the last week when 2012 GOP nominee Mitt Romney speculated there could be a "bombshell" in them, Trump repeated that he has "nothing to hide" and that he'll release them when he is done being audited.

"You don't learn very much from tax returns, let me tell you right now," he said. "But when you're under an audit, you don't give your papers. I've been under audit for so many years. Every year I get audited for I think over 10 years, maybe even 12 years, I've been audited. And I think it's very unfair and I think I'm being singled out."

Trump again defended the hiring practices of a club he owns in Florida, which brought in foreign workers for jobs that Americans had applied for. As he did in the Republican debate on Thursday night, Trump said the club brought in foreign workers because the jobs in question were less-desirable seasonal jobs.

"Well, they have to be qualified. It's at Mar-a-Lago, it's during the season when you can't get people, it's very, very hard to hire people, qualified people," he said. "And a lot of people didn't want the job because it's a three- or four-month job. You know, just during the season, during what we call the hot season, the high season, and it's very hard to get people because it's just one of those things."

Asked about former Central Intelligence Agency Director Michael Hayden's suggestion that the military could disobey Trump's orders if he became president, Trump just said he "disagrees" with Hayden and that it's a dangerous time in the world.

"I don't know what he means by refuse. I can only tell you there's a lot of bad things going on," he said. "They're chopping off heads in Syria, they're chopping off heads all over the Middle East. ... And all I know is that when they start chopping off heads, we have to be very firm, we have to be very strong, we have to be very vigilant. And I heard his statement and I disagree with his statement."