California will double the taxes on guns and ammunition and use the money to pay for more security at public schools and various violence prevention programs under a new law Gov. Gavin Newsom signed Tuesday.

The federal government already taxes the sale of guns and ammunition at either 10% or 11%, depending on the type of gun. The law Newsom signed adds another 11% tax on top of that — making it the only state with its own tax on guns and ammunition, according to the gun control advocacy group Brady.

Newsom — a potential Democratic candidate for president beyond 2024 — has a reputation as one of the country’s most liberal governors. But he has often refused to raise taxes, even for causes he supports like combating climate change.

But it would have been difficult for Newsom to veto this tax increase, given his outspoken support for gun restrictions at the state and national level. Newsom is in the middle of a national campaign to amend the U.S. Constitution to restrict gun sales to people over 21, require extensive background checks, impose a waiting period for purchases and ban the sale of assault-style weapons. Restrictions like that are in place in some states, but not in the Constitution.