At last month’s Democratic National Convention, former President Bill Clinton offered up a keen insight into the budget process. When people asked him how he managed four budget surpluses in a row, he said, “I always give a one-word answer: Arithmetic.”

The commissioners who oversee the Vashon Park District should borrow a page from his book. Indeed, as the district struggles to make sense of its own shaky budget, one fact clearly emerges: Over the last couple of years, expenses have gone up while property tax revenues have gone down. In other words, it appears there’s been an ongoing math problem.

Specifically, income from tax revenues fell from a high of $1.3 million in 2010 to $1.125 million this year, according to the King County Assessor’s Office. Meanwhile, the district’s budget grew from $1.54 million in 2010 to a current spending plan of $1.7 million.

Another pattern also emerges: Previous budgets show an operating reserve of around $100,000. This year, no such reserve is documented on the district’s budget sheet. Instead, there’s a raft of new costs — such as the $140,000 or so that the district is now paying in principal and interest for two non-voter-approved bonds, the largest of which covers a $400,000 debt the park board took on to help build its fields project north of town.

The park board has often drawn people who are champions of one project or another — people who are passionate about one or two outdoor activities in particular. That’s understandable. They’re volunteers, pouring countless hours into what is often a thankless job. But commissioners have another, more fundamental role to play: to hire an executive director who inspires their confidence and to keep a steely eye on the budget. By both of those measures, this board has missed the mark.

As Chairman Bill Ameling pointed out last week, however, it’s easy to play Monday morning quarterback. What’s not so easy is to figure out the best path forward.

To that end, the commissioners seem to be on the right track: They’ve put a hold on the fields project; they’re taking a hard look at the budget; and they’ve begun a search for a new executive director, asking members of the public to step in and play an active role.

The task before them is not fun. What’s more, it’s likely going to get harder. Last year, property values tumbled again on Vashon, meaning that next year, when those lower property values provide the basis for tax collections, the park district will again see its revenue fall.

Clinton delivered up another zinger in his memorable speech last month. “Democracy does not have to be a bloodsport. It can be an honest enterprise.”

As the commissioners work to address the district’s shortfall, they’re engaged in an honest enterprise — the nitty-gritty stuff of public boards. We hope members of the public will put aside their differences, whatever they may be, and support the commissioners in moving forward. These are our parks, our programs, our pool, our fields. We all have a stake in the outcome.