Republican National Committee Chairman Reince Priebus told "Hannity" guest host Tucker Carlson tonight that he's happy to see that all 17 GOP presidential candidates, including Donald Trump, have pledged their loyalty to the Republican Party.

"Today was a good day for our party," Priebus said. "It works in every direction."

Priebus explained that he has to do whatever is necessary to put the GOP in position to win the 2016 election.

Do you really think Trump will follow his pledge if he drops in the polls in several months? Carlson asked.

"Sure, you can rip up whatever agreement you want and say, 'I’ve changed my mind.' But I think that when someone puts their name on a piece of paper and says to the American people that, 'I give you my word,' and when the other candidates raise their hands and say, 'I’m not going to run as an Independent,' I think that means something," Priebus said.

"I think it means something when you run for president. And when Donald Trump was asked today was there anything that would change your mind, he said, 'There’s nothing that would change my mind. This is what I’m doing.'"

Watch more above.

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