A rise in violent crime is endangering slim Democratic congressional majorities more than a year out from the midterm elections and threatening to revive “law and order” as a major campaign issue for Republicans for the first time since the 1990s.

Homicides in cities increased by up to 40% over the previous year, the biggest single-year increase since 1960, a trend that has not abated so far in 2021. Sixty-three of the 66 largest police jurisdictions saw a rise in at least one category of violent crime, ranging from homicide and rape to robbery and assault, according to the Major Cities Chiefs Association. Homicides and shootings have gone up for three straight years in Washington, D.C., and at least a dozen mass shootings were reported nationwide over the weekend.