Hillary Clinton and Donald Trump are sure to have to fend off questions, from the moderator and from each other, about their pasts, particularly surrounding their charitable foundations.

But because Hillary Clinton has spent the past forty years in the public eye, and many of those years as a public official, her scandals have been much more exhaustively investigated. Donald Trump, however, has been a private citizen until just last year when he announced his bid for president. Therefore questionable incidents in his past have received much less scrutiny, or for that matter a Congressional investigation.

And that may just happen, if Donald Trump can pull out a victory in November at the same time that Democrats take control of the Senate. While this isn’t the most likely outcome—a Trump victory would likely signal strong Republican turnout that would likely carry the GOP to a Senate victory as well—it’s not out of the realm of possibility. In fact, as of Monday morning, statistician Nate Silver gives Democrats a better chance, 52.2%, of winning the Senate than he does Hillary Clinton of winning the presidency, which he puts at a slightly lower 51.5%.

The reason this outcome would be important is that Congress has very broad powers, granted implicitly by the Constitution, to investigate pretty much anything it wants. Senate committees, which would be in Democratic hands, have broad powers to subpoena documents in the course of these investigations, which could make all sorts of information embarrassing to Trump, even if they uncover no criminal behavior, public.

Given the fact that a Trump victory would occur against the backdrop of a deeply divided country, most of whom think Trump is unfit for office, Senate Democrats would likely feel justified to launch investigations right away. Here are the top 3 scandals a Democratic Senate may dig into:

Pam Bondi Pay-to-Play:

Donald Trump, through his foundation (more on that below and here), made a $25,000 donation to Florida Attorney General Pam Bondi while Bondi was deciding whether to join an investigation of alleged fraud at Trump University, the GOP candidate’s educational venture. A political group backing Bondi’s re-election, called And Justice for All, said it received the check just four days after Bondi announced she was considering joining the investigation.

A year later, according to the Huffington Post, Trump held a fundraiser for Bondi at his 126-room Palm Beach resort, Mar-a-Lago.

Both Donald Trump and Attorney General Bondi have denied that the donation and fundraising had anything to do with Bondi’s office’s decision not to pursue a case against Trump University, though Trump later had to pay $2,500 penalty to the Internal Revenue Service because the family foundation that made the donation is not allowed by law to give to political campaigns.

But if the scandal was in fact bribery, Trump could be in much deeper trouble than just receiving a fine. House Democrats have called for the Justice Department to launch an investigation, and if they fail to do that before Trump wins the White House, a Senate investigation could uncover proof that could be extremely damaging and possibly lead to an indictment.

Employing Illegal Immigrants

Despite Donald Trump’s public stances on immigration, he has been accused of employing undocumented immigrants multiple times during his long career. The most recent incident was uncovered by Mother Jones magazine in August, which alleged that Trump’s management company illegally employed foreign models. According to the report:

Trump Model Management has profited from using foreign models who came to the United States on tourist visas that did not permit them to work here, according to three former Trump models, all noncitizens, who shared their stories with Mother Jones. Financial and immigration records included in a recent lawsuit filed by a fourth former Trump model show that she, too, worked for Trump’s agency in the United States without a proper visa.

Immigration is another area where the Senate might want to peer into Donald Trump’s past, given his positions on the issue.

Breaking Tax Laws

Donald Trump’s charitable foundation has gotten far less scrutiny than the Clinton Foundation, though in the last months of the campaign that is starting to change. An investigation by the Washington Post found several cases in which the Trump used the foundation’s money to pay business expenses, contrary to IRS regulation. Fortune estimated that this means Trump “would have to pay a total of around $650,000 in excise taxes, refunds, and interest in 2016 to satisfy the IRS’s potential claim,” if the feds decide to investigate and seek restitution. The report continues:

Given the seemingly serious violations already exposed, the IRS could initiate an audit to examine if the Trump Foundation is a sham operated mainly for the billionaire’s benefit. Nonetheless, the IRS has a policy not to make public announcements about investigations. So even if it does investigate, we won’t know. What’s more, the audit would take many months.

That means that whatever is going on at the Trump Foundation, the public won’t find out until after the election. But given how wrapped up the Trump Foundation is in the possibly criminal Pam Bondi scandal, a Senate investigation into that affair could unearth a lot of interesting information about the Trump Foundation’s tax alleged tax violations.