AS AN EXPERIMENT in participatory democracy, Montgomery County’s public financing system for elections, adopted in 2014 and used by a host of candidates in its elections this year, has been a solid success. It encouraged lesser-known candidates to mount campaigns based on small-dollar donations from ordinary residents, encouraged turnout that was sharply higher in this year’s primaries and helped offset the electoral clout of deep-pocketed special interests — namely, the real estate industry and public-employee unions.

Now, having seen how a public financing system benefited the state’s most populous locality, the county council in Prince George’s County is weighing whether to adopt a similar system. It should.

Prince George’s has come a long way since 2010, when then-County Executive Jack Johnson and his wife were arrested in an FBI sting and subsequently pleaded guilty to corruption charges, a scandal that exposed an unseemly culture of influence-buying. A county council more attuned to ethics in government has helped repair things since then; so has Mr. Johnson’s successor as county executive, Rushern L. Baker III (D), who has run a clean administration.

Still, that painful history is recent, and the county would be wise to cement its improved reputation. Passing a public financing system — as the District of Columbia and Howard County have also done recently — would advance that cause.

It would do so by establishing incentives for candidates running for county council and county executive to broaden their supporters to include donors who write checks for no more than $250, which — if there are enough of them — trigger matching funds that favor the smallest donations. (A candidate who qualifies for the system by raising a sufficient number of small-dollar contributions, and refusing corporate, PAC and other such funds, would receive a $7-to-$1 match for donations up to $25, and a $5-to-$1 match for the next $50. )

By incentivizing small donors, the system draws in more participants — and more voters. In Montgomery’s June primaries, turnout increased nearly 30 percent compared with 2014, and six of the nine Democratic primary winners qualified for the public finance system.

For candidates, public financing is a sea change. Rather than spending their days on the phone soliciting $1,000 checks from fat cats, the system incentivizes them to leverage public dollars by working small events — the sort of retail politics that produces more responsive public officials.

The pushback in Prince George’s, where public financing would go into effect in 2022 if a majority of the county council backs it, focuses mainly on the annual price tag, an estimated $1.5 million to $3 million. That’s a legitimate concern given the county’s tight budget, but the benefits outweigh the costs.

Writing in these pages last year, Phil Andrews, a former county council member in Montgomery County who championed the issue there, said, “Without public financing, mega-donors with megaphones drown out voices of the people in the public square and distort public policy.” That’s as true in Prince George’s as in Montgomery.

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