California Democrat Barbara Boxer is the latest U.S. Senator to jump on the medical marijuana legalization bandwagon.

Boxer on Tuesday added her name to the list of sponsors for the bipartisan bill introduced last week by Sens. Cory Booker, D-NJ, Kirsten Gillibrand, D-NY, and Rand Paul, R-KY that would legalize MMJ at the federal level. Republican Sen. Dean Heller of Nevada has also signed on as a co-sponsor of the bill.

The New York Times speculated that Boxer’s weighty name, along with the combination of bipartisanship behind the measure, may give more political clout to the bill.

“Senator Boxer is a strong supporter of California’s medical marijuana law and she believes that patients, doctors and caregivers in states like California should be able to follow state law without fear of federal prosecution,” a spokeswoman for the senator told The Washington Post.

Boxer’s move was welcome news to those backing the measure.

“An old-school pol like Boxer getting on board now after years of barely lifting a finger to protect the will of her state’s voters from federal interference is a sign that the dam is about to break,” said Tom Angell, chair of the Marijuana Majority, in an email. “I’m very optimistic.”