And donors aren’t contacted by 20 different candidates and parties for 20 different checks. While candidates get to save themselves some money, by splitting the cost for fundraising rather than foot the bill themselves.

Joint fundraising committees are great for people with name recognition, with strong fundraising skills, and those facing tight races.

Mayersohn said it’s easy to see why they’re so popular, among Republicans, in particular.

“Republicans are, make much more use of this than Democrats do because Democrats get much more of their money from small donors,” he said.

There are some restrictions. The candidates and entities in the joint fundraising committee have to decide ahead of time how they’re going to split the money. Donors still have to abide by individual fundraising limits, but thanks to the 2014 McCutcheon v. FEC Supreme Court case, there are no aggregate limits. Which, as Erin Chlopak of the nonprofit Campaign Legal Center explained, is helpful for joint fundraising committees who want to find mega-donors.

“Until the McCutcheon decision, there was also a ceiling on the amount that individuals could give to all these different groups overall,” Chlopak said. Outside of the accountability work at the Campaign Legal Center, she spent more than a decade as an attorney at the Federal Election Commission.

The ceiling in 2012 was $46,200 to all federal candidates and no more than $70,800 to PACs and political party committees, according to the FEC. The Supreme Court’s 5-4 decision said the aggregate limits violated the First Amendment. So now that ceiling is gone.

“Theoretically, an individual who wanted to support every single candidate running and every political committee and party would be free to do that,” Chlopak said.

Raising massive amounts of money from a single donor raises concerns for her, because it gives individual donors resources “outsized power to influence candidates and parties.”

There is, however, one silver lining for transparency advocates. Joint fundraising committees make it easier to find big donors. Again, instead of going through 20 different filings looking for a single name, you can spot the big check in the joint fundraising committee filing.

Overall, though, Chlopak doesn't expect the fundraising rules for these committees to change.

“The people who benefit the most from them are the people in power, and they’re unlikely to make changes that would be contrary to their own interest,” she said.

According to the Center for Responsive Politics, the 2016 presidential election year set the record for the most amount of money raised by joint fundraising committees, about $1.2 billion. And 2018 saw an all-time record for the number of joint fundraising committees used at more than 1,500.

The 2020 election cycle could shatter both records. So far, President Donald Trump's two joint fundraising committees have raised more than $96 million and $65 million respectively.