“We think setting criminal-justice policy by constitutional amendment is a terrible idea, and I think what makes it even worse is that it’s not being proposed by Ohioans. It’s being driven by money from out of state,” Tobin said. “We’re going to have to live with the unintended consequences of this.”

Read: Even if you hate Zuckerberg, you’ll love him later.

Zuckerberg’s investment in a ballot measure a long way from home is hardly unique. The liberal billionaire George Soros has given $5 million for issues on the ballot this fall around the country. The California environmentalist Tom Steyer has spent $10 million.

All told, this trio and 22 other American billionaires have invested more than $70.7 million for initiative campaigns this year in 19 states where they do not reside.

Meanwhile, as little as $7.2 million has gone from their wallets and those of other billionaires to campaigns in their home states, according to a Center for Public Integrity analysis of state records.

In total, the $78 million tally from all 34 billionaires—local givers and out-of-state donors alike—may be pocket change to them, but it is more than 10 percent of the $648 million disclosed so far this year for statewide ballot-measure campaigns, as tracked by the nonpartisan political encyclopedia Ballotpedia. And the total is likely an undercount of billionaires’ influence on this year’s ballot measures. It doesn’t include gifts from billionaire-led corporations, or from nonprofits where the billionaires are among a multitude of backers, or from nonprofits whose donors’ identities are unknown.

As with Tobin and the prosecutors association in Ohio, the handouts from the wealthy to campaigns across state lines rankle some local opponents, even though no one questions their legality. Just who should decide issues in their state, they ask—the people who live there, or some rich folks from out of state?

“We believe strongly that a California billionaire coming into Arizona and spending $10 to $20 million to cram this thing down our throats is problematic,” said Matthew Benson, an opponent of a renewable-energy measure in Arizona backed by Steyer that would require utilities to get half their power from wind and solar sources by 2030.

Other local activists say it’s fine to have billionaires funding ballot initiatives, which let voters decide issues directly. “There’s nothing illegal about this,” said the initiative expert and University of Florida professor Daniel Smith. “In some ways, it’s less corrupt than if they were making contributions to lawmakers or giving favors to lawmakers.”

Indeed, the Supreme Court ruled in 1981 that states cannot limit contributions to ballot measures partly because measures, unlike candidates, cannot be corrupted.

Billionaires and ballot measures are not a new combination. The oil-industry magnate John D. Rockefeller was behind a 1912 Colorado referendum campaign to eliminate an eight-hour maximum workday for miners. The California software developer Ron Unz funded a Colorado initiative in 2002 to ban bilingual education. Former New York City Mayor Mike Bloomberg has funded campaigns in California to hike cigarette and soda taxes.