California Lt. Gov. Gavin Newsom.

America’s attitude toward marijuana use, recreational and otherwise, has changed drastically over the past 20 years. In fact, California now stands as the only west coast state where adults can’t buy marijuana without a doctor’s recommendation, now that Oregon has opened legal cannabis stores.

With polls showing a majority of Americans in are in favor of an end to cannabis prohibition, it seemed legalization in California was inevitable. But now, many aren’t so sure, as the legislation’s biggest supporter, California Lt. Gov. Gavin Newsom, seems to have abandoned the cause in order to jump on the gun debate bandwagon.

Last week, Newsom—who endorsed legalization shortly after Colorado and Washington passed such legislation in 2012—announce he’s backing a ballot initiative on gun control, according to this story from SFWeekly.

Political observers say this will likely take precedence over marijuana legislation for Newsom in 2016, who plans to run for the governor’s seat in 2018, the story says.

The gun control push Newsom has backed includes a proposed ban on magazines with a capacity of more than 10 rounds, and would also require background checks for all ammunition purchases in California, according to this story

The San Francisco Chronicle says it will keep Newsom so busy he will have little time to get deeply involved with the marijuana initiative. Newsom told the Chronicle the gun issue “is a very deep issue for many of us, particularly those of us with children.”

As the story points out, Newsom has not mentioned what will happen to ammo sales over the Internet should background checks be required. It could lead to a ban on all ammo purchases in California, or require them all to be shipped to an FFL where a background check would be performed.

There has also been no discussion of plans for pre-existing ammunitionsold before the legislation would take effect, and if the legislation would extend to reloading components such as bullets, propellant, or primers.