The influence of the National Rifle Association, the nation’s highest-profile Second Amendment-rights organization and a longtime powerhouse against gun-control laws, is showing signs of potential decline.

The NRA’s own tax forms show a dip in revenue. And even as the group, now under the leadership of new president Oliver North of Iran-Contra fame, continues to spend big money on federal lobbying and political campaigns, its opponents in the gun-control movement, after decades of ever more deadly mass shootings and seemingly random incidents of gun violence, have been on the rise.

During the 2018 midterm elections, for example, gun-rights groups spent some $9.9 million on outside political efforts, nearly all of that from the NRA, while gun-control groups invested a record high of $11.9 million, according to a tabulation from the nonpartisan Center for Responsive Politics.

Andrew Arulanandam, a spokesman for the NRA, calls the decline in revenue between 2016 and 2017 temporary.

“Right now, we are at the highest levels of membership,” he said, with 5.5 million dues-paying members, the most in its 150-year history. “More people identify with the NRA and believe in what the NRA stands for than ever before.”