Gavin Newsom wants a 28th Amendment to the United States Constitution—and he wants it to be about gun control. In an interview with POLITICO, Newsom outlined his vision for the amendment, which would institute a constitutional ban on assault rifles, universal background checks, and a “reasonable” waiting periods for firearm sales, and raise the federal minimum age to purchase a gun to 21. The plan, which Newsom is funding with leftover campaign cash, is a longshot at best; Democrats control only 20 state legislatures, while a constitutional amendment would require approval from 38. But Newsom has championed the issue for years, and the amendment signals his frustration with a Congress and Supreme Court that has recently stymied and at times undone gun control measures. “We’re sick of being on the defense and throwing up our hands,” Newsom told POLITICO. “We want to go on the offense and be for something and build a movement that’s bottom up, not top down.”