Secret donor-funded “dark money” spending reported to the Federal Election Commission has officially exceeded $1 billion according to a new analysis by the Center for Responsive Politics, and that barely begins to scratch the surface of political spending by groups that don’t fully disclose their donors.

Along with another billion dollars spent by partially-disclosing groups that keep some donors hidden or are funded by dark money sources, spending by groups that don’t fully disclose donors has exceeded $2 billion since the 2006 election cycle.

Direct dark money spending by groups funded entirely by anonymous donors hit nearly $150 million reported to the FEC for the 2018 election cycle alone. That doesn’t include additional money funneled to other groups spending in elections or spent on political ads couched as issue advocacy and digital advertising that remains largely untouched by FEC disclosure requirements. Dark money has hardly waned. Instead, it has begun manifesting in new forms that are often harder to track and quantify.

More than half of all 2018 election spending by outside groups, excluding party committees, was by groups that do not fully disclose their donors.