Vice President Kamala Harris has proposed a ban on “price gouging” by food suppliers and grocery stores, as part of a broader agenda aimed at lowering the cost of housing, medicine, and food. The proposal, introduced Friday, is an attempt to tackle a clear vulnerability of Harris’ head-on: Under the Biden-Harris administration, grocery prices have shot up 21%, part of an inflation surge that has raised overall costs about 19% and soured many Americans on the economy, even as unemployment fell to historic lows. Wages have also risen sharply since the pandemic, and have outpaced prices for more than a year. Still, surveys find Americans continue to struggle with higher costs.