Now in its ninth month, the war in Iran has hit American pockets hard, and it could shift the balance in key midterm races that decide who controls Congress.

The serious damage to refineries and other facilities in the Middle East, combined with ongoing uncertainty about whether the Strait of Hormuz will remain open , have kept oil prices inflated. Americans have paid for it: The Center for American Progress estimates that the war has cost each US household at least $1,200.

Rising costs are among the reasons the war has been deeply unpopular, and Tuesday’s midterms are likely to be a referendum on how the White House has handled the impact. Democrats are trying to use that to their advantage to win races in places where the high price of diesel, home heating oil, and fertilizer are particularly top-of-mind for voters.…