MYRTLE BEACH, S.C. -- Republican presidential candidate Donald Trump took credit for a prisoner swap between Iran and the United States that brought home four Americans, including a reporter for the Washington Post, on the same day that United Nations inspectors said that Iran has met its obligations under a landmark nuclear deal reached with six world powers.

"So I've been hitting them hard and I think I might have had something to do with it," Trump told a crowd of activists at the South Carolina Tea Party Convention. "You want to know the truth? It's a part of my staple thing, I mean, I go crazy when I hear about this, you go absolutely wild because how is it possible?"

Trump has castigated the Iran nuclear deal for months - making it a significant portion of his stump speech. At many campaign rallies, Trump receives a loud cheer from the crowd as he calls Secretary of State John Kerry an incompetent negotiator.

Republican presidential candidate Donald Trump speaks at the South Carolina Tea Party Convention at the Springmaid Beach Resort in Myrtle Beach, South Carolina, Jan. 16, 2016. TIMOTHY A. CLARY/AFP/Getty Images

Even though he believed he was due some credit for the prisoner exchange, Trump made clear that he didn't think that the deal was fair to the United States.

"First of all, it should have taken place three or four weeks ago, whenever the hell they started," Trump said. "Did you ever see an agreement take so long as this agreement? How long has this thing been going on? Years and years."

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Throughout the campaign, Trump has shown a propensity for making dubious claims of credit. On Christmas Eve, Trump tweeted that it was because of his pressure that the Department of Homeland Security announced an operation for mass deportations of thousands who came to the United States from Central America.

Wow, because of the pressure put on by me, ICE TO LAUNCH LARGE SCALE DEPORTATION RAIDS. It's about time! — Donald J. Trump (@realDonaldTrump) December 24, 2015

Trump also said he was responsible for ABC removing a New Hampshire paper, The Union Leader, as a sponsor of an upcoming Republican debate -- a claim that ABC never commented on.

So professional of @ABC news to throw out the failing @UnionLeader newspaper from their debate. Paper won't survive, highly unethical! — Donald J. Trump (@realDonaldTrump) January 11, 2016

In October, at a rally in Las Vegas, Trump said he was partially the reason that House Majority Leader Kevin McCarthy ultimately chose not to run for Speaker.

"They're giving me a lot of credit for that because I said you really need someone very, very, tough and very smart," Trump said.

Also in October, Trump tweeted that Ford, because of his "constant badgering" was canceling a plan to build a plant to Mexico.

Word is that Ford Motor, because of my constant badgering at packed events, is going to cancel their deal to go to Mexico and stay in U.S. — Donald J. Trump (@realDonaldTrump) October 25, 2015

The tweet turned out to be inaccurate, according to Ford, which issued a statement saying, "Ford has not spoken with Mr. Trump, nor have we made any changes to our plans."

Trump's tweet was referring to Ford's plan to move production of certain trucks to Ohio, a decision made in 2011.

The examples are seemingly endless. In 2012, Trump took credit for eventual Republican nominee Mitt Romney's win in the Nevada caucuses, which came after Trump's endorsement.

"There was a lot riding on that particular race in Nevada and it was interesting, because the numbers were much, much greater than you thought," Trump said at the time in an interview with Fox News. "And a lot of people are giving me credit for that. And I will accept that credit."