Donald Trump has made tons of money investing in office buildings, condo projects and golf courses. Yet Trump boasts that he gets the most for his money from another type of investment: campaign contributions to politicians. According to the tycoon-turned-Republican presidential nominee, the politicians he’s funded invariably rush to his side whenever he needs them. “When I want something I get it,” he declared at an Iowa rally in January. “When I call, they kiss my ass. It’s true.”

But now, Trump’s $25,000 gift to Florida’s attorney general is stirring a blizzard of controversy. Critics claim that the contribution swayed AG Pam Bondi’s decision not to investigate scandal-plagued, now-defunct Trump University.

The story of how a Bondi PAC received a big check from Trump Tower just days before the AG declined to probe Trump U, how the money arrived as an illegal gift from, of all sources, Trump’s charitable foundation, and the remarkable string of coincidences the Trump camp claims led to an innocent error, forms one of the most intriguing, ongoing subplots of the presidential campaign.

Here are five things to know about Trump’s donation to Florida’s attorney general:

Trump and Bondi Have a Long History of Mutual Support

A former prosecutor and Fox News legal analyst, the telegenic Bondi was first elected Attorney General in 2011. She supported Trump over Florida favorite son Marco Rubio in the March Republican primary. Standing beside the mogul at a Tampa rally, she declared: “We’ve been friends for years. I know his family personally. I’ve seen first hand how he leads.” Bondi was also one of the top female supporters to speak at the Republican convention in July, and reportedly participates in conference calls with Trump’s top advisers.

As a renowned developer in Florida, Trump backed Bondi — long before he became a presidential contender. It’s the big check written to her successful, 2014 re-election campaign the previous year that’s brought charges of corruption. It’s also worth noting that Trump held a $3,000-a-plate fundraiser for Bondi in March of 2014 at his Mar-a-Lago resort in Palm Beach, just six months after her office decided not to investigate Trump U.

Bondi Had Been Criticized Over the Suspicious Timing of the Donation

On August 25, 2013, New York Attorney General Eric Schneiderman filed a civil suit against Trump University and its affiliates, its former president and Trump himself for allegedly defrauding more than 5,000 customers of over $40 million they’d paid to attend real estate seminars that failed to deliver on their elaborate promises. The Orlando Sentinel reported numerous Floridians’ making similar claims, and on September 14, 2013, the Orlando Sentinel reported that a Bondi’s spokesperson told stated that the Florida AG was “reviewing the New York lawsuit’s allegations,” and was deliberating on whether to join the New York AG’s case.

Four days later, a pro-Bondi PAC, And Justice for All, received a check from the Donald J. Trump Foundation for $25,000. In mid-October, Bondi’s office told the Florida press that “no action was necessary” and that Florida residents would be compensated under the New York action since it covered all consumers nationwide.

(UPADE): A spokesman for the Florida Attorney General, in an email to Fortune, strongly denied that the AG’s office ever stated that it was considering whether to join the Schneiderman suit. Hence, the Bondi office is denying the report in the Orlando Sentinel that the AG’s office was considering that course.

In the email to Fortune, spokesman Whitney Ray stated: “All articles misreporting that this Office made a determination not to investigate or sue Trump University in 2013 stem from a 2013 reports that erroneously stated that this Office was reviewing the New York lawsuit’s allegations ‘to determine whether Florida should join the multi-state case.’ This was absolutely not true.”

Ray stated further, “The records show a staff member briefly reviewed ‘the allegations of the New York complaint to see if it had any relevance to Florida.’ We never stated that we were reviewing the allegations to determine whether we would join a ‘multistate’ action, as none existed.”

Although Trump denied he’d ever discussed Trump U with Bondi, and praised her as “a great representative of the people,” during Bondi’s 2014 campaign, the Democrats and the media pounded Bondi over the suspicious timing of her decision.

It wasn’t until June 6, 2016 that a Bondi spokesperson told The Associated Press that Bondi had personally solicited Trump for a contribution around the same time her office was being asked about its investigation of Trump U.

Bondi’s office claimed that it received just one complaint about Trump U between the time she took office in 2011, and the contribution in mid-September of 2013. However, it’s been widely reported that Bondi’s predecessor received over two-dozen complaints from folks who claimed they’d been scammed by Trump’s seminars. And the Schneiderman suit includes no fewer than complaints for damages on 827 Trump courses taken by Floridians.

Trump’s Staff Claim a Remarkable Series of Errors Led to Misreporting the Contribution

The wonder is that the press, Bondi’s critics, and Trump’s opponents somehow missed that the money came from Donald J. Trump Foundation, a charity that, under IRS rules, is barred from engaging in politics. On March 21, two years after the pro-Bondi PAC received its $25,000 check from the Trump Foundation, a left-leaning watchdog called Citizens for Responsibility and Ethics in Washington filed a complaint with the IRS.

CREW cited IRS regulations stating that public charities “are absolutely prohibited from directly or indirectly participating in, or intervening in, any political campaign.” The complaint charged that the Foundation’s donation was strictly illegal, and that in its IRS filings, Trump had attempted to camouflage the real destination of the funds (although the PAC’s filings clearly stated that they flowed from the Trump Foundation, a revelation that went mainly unnoticed for more than two years).

At Trump Tower, the staff sprung into damage control. A staff that prides itself on rarely apologizing admitted to a remarkable series of errors. In interviews, the Trump braintrust–Allen Weisselberg, CFO of the Trump Organization and treasurer of the Foundation, and other Trump executives –gave an intricate explanation of how they occurred. Shortly after Bondi asked Trump for a contribution, they said, a request for payment arrived at Trump’s headquarters in September, 2013. The clerk who received the RFP didn’t recognize the name And Justice For All, and mistook it for a charity. He was under a standing order to verify that charities requesting donations were bona fide by checking their names in an official registry.

The clerk found a charity with the same name, And Justice for All, in Salt Lake City, Utah, and wrote a $25,000 check from the Trump Foundation to that And Justice for All. But the funds didn’t go to the anti-abortion group in Utah that provides legal assistance for people with disabilities. Instead, the check went to the pro-Bondi PAC in Tampa.

The Trump staff was unable to explain why, if the money was intended for the Wichita charity, it was mailed to a different address in Florida.

CREW found a second error that elicited yet another interesting explanation from Trump staff: When the Donald J. Trump Foundation filed its annual report with the IRS (called a form 990), it reported the $25,000 gift to still another charity named Justice for All (no “and,” as in the PAC) based in Wichita, Kansas. This organization that collaborates with local church groups to train anti-abortion activists received no funding from the Trump Foundation. The Trump brass blamed this error on the Foundation’s accountant. “From what I’m told they made a typographical mistake on the return,” explained Weisselberg, who added that these types of things happen “all the time.”

After the CREW filed its complaint, Trump personally paid a $2,500 penalty, equivalent to 10% of the illegal donation, to the IRS. The PAC supporting Bondi, obviously embarrassed, mailed a $25,000 refund to the Foundation. Trump declined to cash the check, and instead reimbursed the Foundation for the full $25,000 from his own funds. Hence, the pro-Bondi PAC kept the money.

The $25,000 Donation Was A Lot of Money for the Trump Foundation

Donald Trump founded his eponymous foundation in 1987 to distribute the profits from his bestseller, “The Art of the Deal.” But in recent years the tycoon hasn’t contributed any of his own funds; all of the donations have flowed from his friends and supporters.

In 2013, it made 71 grants and donations totaling $591,000. Many of the recipients are renowned: The Nicklaus Children’s Health Care Foundation ($100,000), and the American Cancer Society ($60,000), and some less so, such as the Drumthwacket Foundation ($10,000) that supports the historic residence of New Jersey’s governor, currently Trump enthusiast Chris Christie.

By the Foundation’s standards, a $25,000 gift is highly significant. It’s tied for sixth highest with four other $25,000 donations, including the Palm Beach Zoo, and exceeded contributions to the New York City Police ($15,000), the Joe Torre Safe at Home Foundation ($5,000) and Mount Sinai Children’s Center ($2500).

As for And Justice for All (the PAC, that is), the $25,000 contribution was also pretty significant. It raised just over $1 million for Bondi’s 2014 campaign, and the $25,000 was tied for fourth, equaling that of the Sunshine Gasoline Distributors.

This Controversy Isn’t Going Away

The Washington Post, among others, have raised questions about other expenditures made by the Trump Foundation. It’s also likely that press and the Clinton campaign will keep the spotlight on three puzzling issues: whether Trump’s $25,000 contribution influenced Bondi’s decision not to investigate his notorious seminar school, how his foundation came to make the illegal gift, and how the foundation’s tax return listed the money as going to a Utah charity that received nothing.

Imagine that Trump wanted to support a political pal with other people’s money. What better idea than to use his foundation’s cash, since it’s all funded by others, and hide the payment from the IRS by finding a charity with an almost identical name? Of course, we don’t know if that really happened. But it’s what the CREW and other critics are charging.

Two things lend that view at least some plausibility. First, how did the $25,000 ever go to Florida, and a PAC, when the clerk thought he was writing a check to a charity with an address in Wichita? Second, $25,000 is a lot of money for the Trump Foundation. It appears that it knew nothing about the abortion-opposing activities of the Wichita group, did nothing to check it out, and still said it made an error in not sending one of its biggest donations in response to a mysterious request for payment, arriving from an unknown charity.

As for why the “clerk error” of wrongly sending the check to Tampa was followed by the “typographical error” of telling the IRS the money went to still another charity of still another similar name, that’s a screwup sans an obvious explanation. Why claim the money went to Utah when you first wanted it to go to Kansas? If it’s your intention, you’d disguise the real payment either way.

CREW isn’t ready to let the issue die. On September 7, the watchdog group filed a second complaint demanding that the IRS investigate whether Trump Foundation and Donald Trump may have violated federal tax law relating to charities. In the complaint, CREW states that if the IRS finds that Trump and his foundation did indeed use the foundation for political purposes and intentionally misrepresent the source of the funds, its tax free status should be revoked, and the matter should be referred to the Department of Justice.