One of these days, the November election campaign will get under way. When that day comes — perhaps by Labor Day, certainly by Halloween — the voting public will want issues by which to sort out candidates for governor and the Legislature.

There is no shortage of possibilities. The persistent stagnation of the Northern Maine economy, Maine’s last-place position in investing in research and development, its low college attainment, the east-west highway and other rural transportation needs, poverty, health care, child abuse, property taxes, to name but a few.

But in the perverse way politics has of ignoring the complex and elevating the simple, what is shaping up as the No. 1 campaign issue is one of the most irrelevant — the sales tax.

Thanks to a swelling revenue surplus, the 6 cent sales tax will drop by a half-cent in October. That’s the law and it will occur unless the Maine Supreme Judicial Court finds something in that law no one else sees. There may be better ways for the state to give back $60 million to the taxpayers, but so be it.

Not content with that, a small but noisy number of pols, both incumbents and hopefuls, want to make a full-cent sales tax cut the litmus test for voters. In a state facing serious issues that deserve serious debate, they want a yes-or-no answer. Even worse, some sitting legislators, Republicans and Democrats, are pestering Gov. King about calling the Legislature into special session for a vote on reducing the tax.

The governor has responded to the special-session call by pretending not to hear it, and for that the state should be grateful. The Maine constitution empowers a governor to order lawmakers back to work in extraordinary circumstances. A revenue surplus is nice, especially given the state’s history of poor-to-mediocre economic performance, but it is hardly extraordinary. Maine simply does not need the expense of a special session, or of the pre-election posturing it would bring.

Besides, this Legislature is done, and for that, too, the state should be grateful. This Legislature has absolutely no business making a $60 million decision that the next will have to deal with.

For this Legislature already has made one decision that the next absolutely will have to deal with and it is closely tied to all sources of state revenue, including the sales tax. It’s what, in polite company at least, is called the structural gap.

The gap, the difference between projected state spending and projected state income for the coming biennium is estimated at some $300 million. In the red. That’s what this Legislature left behind. That’s a real campaign issue.