After Colorado voters legalized marijuana, they also approved heavily taxing it and using the money for school construction, law enforcement, drug education and other useful things. The arrangement made perfect sense.

But now the 15-month-old experiment has entered a phase that makes no sense at all. It’s the prospect that all this new marijuana revenue — an estimated $58 million in the current fiscal year — may have to be returned to the voters, because of a provision in the state’s Constitution that rigidly constrains taxes and spending. The provision is the Taxpayer’s Bill of Rights, or Tabor, a complex set of rules that requires, among other things, voter approval of all new taxes and automatic refunds if tax revenues or spending exceed estimates given when tax questions are put to the voters.

As an April 1 report in The Times explained, Colorado’s tax revenues have recently surged, thanks in part to the booming construction, oil and gas industries, in addition to some $58 million from the marijuana taxes. But not only revenues but overall state spending this year are expected to end up higher than the state estimated back when the marijuana tax was on the ballot. Under Tabor — which some in Colorado have likened to a fiscal straitjacket or a statutory version of the crazed space computer HAL 9000 — the state is therefore required to refund the marijuana money.

But lawmakers don’t want to give the money back. They argue that marijuana was always supposed to pay for itself, that school spending in particular is a vital public priority and that the general fund should not be tapped to make up for one missed revenue estimate. They are also vexed by the question of who should get the money — weed growers and buyers, or the general public? — and how to give it back.