Voters in San Francisco will go to the polls on Tuesday to decide whether the city should ban flavored nicotine products, including vaping fluids.

The ban on flavored tobacco and vaping products is being presented as a necessary measure designed to improve public health and as a way to keep nicotine away from children. But if Proposition E is approved by voters, it could make it more difficult for smokers to kick their tobacco habit. By prohibiting relatively safer and more attractive options, San Francisco could create a set of incentives that leaves nicotine-addicted residents sucking on the cancer sticks.

San Francisco's proposed ban is the most high profile example yet, but it's merely part of an ongoing trend of cities across California taking steps to prohibit flavored nicotine products from being sold to anyone regardless of age. Sonoma, Berkeley, and Manhattan Beach have passed ordinances banning the sale of flavored tobacco products and some flavored vaping fluids. Similar bans have been passed but not yet implemented in Beverley Hills, Palo Alto, San Mateo, and elsewhere.

As I wrote in April, there cities are moving in exactly the wrong direction, as a growing body of scientific and medical evidence demonstrates that vaping helps smokers quit.

In January, the National Academies of Sciences, Engineering, and Medicine issued an advisory opinion to the Food and Drug Administration (FDA) showing that e-cigarettes could be life-savers. "E-cigarette aerosol contains fewer numbers and lower levels of most toxicants than smoke from combustible tobacco cigarettes does," wrote University of Washington toxicologist David Eaton, who authored the report. "Laboratory tests of e-cigarette ingredients, in vitro toxicological tests, and short-term human studies suggest that e-cigarettes are likely to be far less harmful than combustible tobacco cigarettes."

A victory for Prop E would be a big loss for public health, says Michelle Minton, a senior fellow at the Competitive Enterprise Institute, a free market think tank in Washington, D.C.

"They are using the specter of big tobacco targeting children to convince voters to institute stricter regulations that will make e-cigarettes harder to get, more expensive, and less attractive than actual cigarettes," Minton writes.

In San Francisco, backers of the ban have claimed opposition comes from Big Tobacco and have disregarded the many small businesses that could be forced to close or move if Prop E passes. Tobacco companies have "shrewdly allowed local shop owners to serve as the sympathetic face of the campaign, arguing that local pols looking to beat up on Big Tobacco are actually putting mom and pop out of business," the San Francisco Chronicle claims in its editorial advocating for a "yes" vote on Prop E.

It's true that big tobacco companies like R.J. Reynolds have spent more than $11 million opposing Prop E. But that doesn't begin to compare to the more than $75 million the California Department of Health has spent on a new anti-vaping campaign—funded by taxpayers—that's been hitting California TVs since January.

And the Prop E advocates basically ignore the fact that the ban on flavored nicotine products will do real damage to real businesses in San Francisco. Dozens of business owners protested the proposed ban outside of city hall in April.

"We just legalized marijuana. Now you want to ban menthol cigarettes?" Shawn Richard, one of those protesters, told a local TV station. "I mean come on. For real? That doesn't make any sense."

Only in California, Shawn.