Will voters try to repeal California's 21+ smoking age law?

California became the second state to push the age for buying tobacco to 21, but the response by tobacco companies – and voters – in the coming months will show whether raising the age limit truly has national appeal.

The bill criminalizes selling or giving tobacco to Californians who are younger than 21. Gov. Jerry Brown (D) signed it Wednesday alongside four similar measures, but opponents have threatened to challenge the law by referendum. They have until August to gather 366,000 signatures for the bill to make the November ballot. 

"The fierce opposition from Big Tobacco on this measure proves just how important this law is and how much their business model relies on targeting our kids," the bill's author, state Sen. Ed Hernandez (D), said in a statement.

California's bill stalled for six months because veterans groups and Republican legislators said that anyone old enough to die for their country as part of the armed forces was old enough to make decisions about tobacco use. A compromise broke the stalemate, so the bill exempts military personnel from the change.

The concern also came up when Hawaii passed a similar bill in April.

"I can't stand cigarette smoking. It's disgusting," Hawaii state Rep. Angus McKelvey (D) told The Associated Press in June, when that state became the first to ban tobacco sales to anyone under 21. "But to tell somebody you can go and fight for your country and get killed but you can't have a cigarette, that's the thing."

Challengers to the bill face momentum based on the success of one study in Needham, Mass., which showed raising the age to 21 can help reduce underage smoking. The city raised the legal age for buying cigarettes to 21 and saw teenage smoking rates drop more than in surrounding suburbs.

Researchers attributed the decline to social networks, as 18-year-olds could no longer pass cigarettes on to underage friends. By age 21, cigarette-users were much less likely to have 16- or 17-year-old friends, as Jessica Mendoza reported for The Christian Science Monitor.

"When you increase the minimum sales age, you're not only reducing teenagers' direct access to cigarettes," Shari Kessel Schneider, co-author of the study and project director at the Health and Human Development Division at the Education Development Center in Massachusetts, told the Monitor. "You're also reducing the social sources who may be giving them cigarettes."

The idea has caught the attention of cities around the nation – and the US Food and Drug Administration, which requested a study on its probable impact on young tobacco users. It estimated 90 percent of daily smokers started by age 19, according to findings by the Institute of Medicine.

"There's a huge amount of momentum around this right now," Micah Berman, an assistant professor at the Moritz College of Law and the College of Public Health at Ohio State University, told the Monitor. "There's a lot more research coming out all the time on the effects of nicotine on the adolescent brain, and [the policy] is incredibly popular. Even people who are current smokers don't want the next generation of kids smoking."

This report contains material from the Associated Press.