Motorists don’t like to pay more at the pump, and lawmakers worry that if they raise taxes on gasoline, they’ll be voted out of office. But states rely on those taxes to build and maintain roads and bridges. With revenue lagging, those structures have been falling into disrepair in many places. Despite the tough politics, 26 states have raised taxes on motor fuels in the past four years. The eight states that raised taxes this year include Tennessee and South Carolina, deep-red states dominated by fiscal conservatives.Lawmakers say the sorry condition of their state’s roads and bridges compelled them to act.