California’s escalating housing costs have yielded epic commutes and a rising tide of homelessness. Now they are close to producing a political milestone: a vast expansion of tenant-protection laws that would cap rents statewide.

On Tuesday, the State Senate voted to advance a bill to limit rent increases to 5 percent a year plus a cost-of-living adjustment. The State Assembly, the Legislature’s lower house, could give final approval as early as Wednesday, though passage is uncertain.

The legislation is the latest in a series of measures that have swept through state and local governments this year to regulate rents and strengthen tenant rights. For decades, such provisions have been mostly limited to a relative handful of apartments in the nation’s big cities.

“Passing tenant legislation in Sacramento is incredibly difficult,” said Assemblyman David Chiu, a San Francisco Democrat who is the bill’s author. “But we’re in the midst of the worst housing crisis in our state’s history, and I think my colleagues and policymakers understand we have to do something differently.”