One category of politically related spending is less regulated than others in the U.S., and states are moving in opposite directions when it comes to disclosure requirements. Here are questions and answers about the so-called dark money involved in political races.

Q. What is “dark money?”

A. It’s what critics call political spending by nonprofit groups that do not report the sources of their contributions. The money generally comes from nonprofits registered as social welfare organizations and goes toward independent spending rather than campaign coffers controlled by candidates. The federal government does not require those groups to disclose their individual donors, and neither do most states.

Q. How much of a factor is this kind of spending in elections?

A. It accounted for more than $300 million in the 2012 presidential and congressional elections, and is expected to play a significant role in 2016. An analysis of TV ad buys seeking to influence state-level campaigns in 2014, released by the Center for Public Integrity, found that $25 million was spent by groups that did not disclose their donors.

Q. What do courts say about this?

A. They had a role in creating it. The U.S. Supreme Court’s Citizens United ruling in 2010 found it unconstitutional to put limits on political spending by businesses, unions and nonprofit groups. That case and others have altered the democratic process, with political spending increasingly done by outside organizations rather than candidates or parties. The Citizens United ruling also encouraged prompt disclosure as a way to hold corporations and candidates accountable.

Q. So have lawmakers responded with a push for transparency?

A. Far from it. Many states have not updated their campaign finance laws in reaction to “dark money” spending, and some are going the other way: Gov. Scott Walker backed Wisconsin legislation allowing political campaigns to coordinate spending with advocacy groups that do not have to disclose their donors.

Q. What’s the argument against disclosure?

A. Attorney James Bopp, who represents conservative groups fighting campaign finance regulations, calls it a free speech issue, because naming the sources of advocacy group donations would chill certain voices. “For the speech-police types that I’m fighting, their goal was never disclosure,” he said. “They’re trying to shut us down.”

Q. Are any states trying to shine a light on dark money nevertheless?

A. Some. Rhode Island and Massachusetts are requiring top donors to be listed on independent advertisements. In California, groups that spend more than a certain amount on political ads are required to report their donors to the state. In Maryland, donors will have to be disclosed unless they specifically tell the organizations that they do not want their money used for political ads.

“The overall trend in the disclosure world is going toward more and better systems,” said Edwin Bender, executive director of the Helena, Montana-based National Institute on Money in State Politics, which tracks political spending and advocates for transparency.

Q. Are the new laws having their intended effect?

A. In most cases, it’s too early to tell. Montana and Maryland get their first tests in 2016. Jonathan Motl, Montana’s commissioner of political practices, vows vigorous enforcement, and says that even if there are “glitches in the system,” whatever it does “is a heck of a lot better than what we’ve had before.”