We’re surprisingly close to our first constitutional convention since 1787. Bad idea.

THE LAST time the United States held a constitutional convention was in 1787. That one turned out pretty well. The next one could have far more doleful results. And the nation is much closer to convening such a convention than many people realize.

It would take the votes of 34 state legislatures to call a constitutional convention to order. A majority of legislatures already have voted to do so. Such calls remain valid indefinitely — until 34 states have joined in a particular cause or the states rescind their appeals. Therefore we congratulate Maryland’s House of Delegates, which on Tuesday rescinded its call for a federal constitutional convention decades after approving it. Same to Nevada’s Senate, which voted, also Tuesday, to rescind a resolution in that state. But a number of states have recently passed or are close to passing measures calling for a convention.

The possibility was mostly dormant from the 1980s until a few years ago, when some blue states began calling for a convention to undo the Supreme Court’s Citizens United ruling and conservative groups began pressing red-state legislatures to pass convention resolutions on a variety of pet causes, including a balanced-budget amendment.