BY SQUASHING a Republican scheme to seize control of the VirginiaSenate by extra-constitutional means, William J. Howell (R), speaker of the House of Delegates, preserved not only the rule of law in the General Assembly but also a glimmer of hope that lawmakers will at last forge a strategy to address the approaching collapse in state transportation funding.

Now it is up to Senate Democrats to reciprocate by joining forces with Republicans to pass Virginia’s first major transportation bill in a quarter-century. Even if a portion of the new funds for transportation will be diverted from schools, health care, public safety and other core priorities, Democrats cannot continue to reject measures that will enable the state to build roads and rails.

Mr. Howell came under tremendous pressure after his GOP colleagues in the Senate sprang their ambush last month. Taking advantage of the absence of a single Democratic senator, Republicans rammed through a surprise bill to radically redraw the electoral boundaries for the Senate, now evenly divided, so that it would tilt sharply into the Republican column. Under the Republican map — drafted in secret, unveiled without warning (even to the governor) and approved with minimal debate — eight of the Senate’s 40 districts would be reworked to disperse black voters, thereby improving the GOP’s prospects.

The sneak attack flew in the face of the state constitution, which specifies that redistricting should occur just once a decade, after the decennial census. (The last redistricting was enacted in 2011.) Still, the Republican subterfuge worked, and the Senate sent the redrawn map to the House, where its fate rested squarely in Mr. Howell’s hands.

For the House speaker, the path of least resistance would have been to send the legislation to the floor, where the large Republican majority would have rubber-stamped it, relegating the Democratic Party to minority status in the General Assembly for years.

That would have enraged Democrats and doomed the already iffy chances that the legislature would pass a transportation funding bill. As things stand now, Virginia will run out of money to pay for new highways, rail and bridges by 2017. And Gov. Robert F. McDonnell (R), now in his last year in office, badly wants a new funding scheme, both to tackle that crisis and to burnish his legacy.

After consultations with the governor, Mr. Howell, with masterly understatement, announced Wednesday that he killed the redistricting plan because it had “dramatically” modified a bill whose original intent was to make minor technical adjustments to the electoral map. In doing so, he not only kept the peace in Richmond, he also left open the possibility that the legislature will remain a place that concerns itself with the people’s welfare, not just partisan warfare.