D.C.’s mayoral race turned negative. Soaring utility bills lit the fuse.

Utility bills are not typically the stuff of brass-knuckle politics in D.C. mayoral races. But the soaring expense of gas and electricity bills, universally squeezing the wallets of D.C. residents and businesses alike, has lit a fuse in the campaign between Democratic front-runners Janeese Lewis George and Kenyan R. McDuffie, driving brittle political attacks this week and…