WASHINGTON — U.S. inflation accelerated last month as gas prices spiked in the wake of renewed fighting in the Middle East, underscoring the affordability challenges that are top of mind for many voters with midterm elections now just seven weeks away. The consumer price index rose 3.4 percent last month compared with a year ago, the Labor Department said Friday, just like July. But inflation quickened month to month as costs jumped 0.4 percent from July, quadrupling the 0.1 percent registered in the previous month. Inflation remains stubbornly elevated more than five years after prices soared as the economy emerged from the pandemic. Friday's report increases pressure on the inflation-fighters at the Federal Reserve to boost their benchmark interest rate next week, which could lift mortgage and auto loan costs in the months ahead. Federal Reserve Chair Kevin Warsh and other Fed officials have signaled they would need to see continuing disinflation to leave rates where they are. "Today’s August report did not deliver that,” said Kathy Bostjancic, chief economist at Nationwide. Price