California's Democratic-drawn map crammed two Republican incumbents — Rep. Ken Calvert (30-year Appropriations veteran) and Rep. Young Kim (three-term swing-district survivor) — into a single seat, the new 40th District, ahead of the June 2 primary. NBC News has the breakdown: a narrow majority of the new district's residents come from Calvert's current turf; roughly a third from Kim's.

The ugliness is now operational. Calvert's campaign linked Kim's past Trump criticism to political violence, prompting Kim to tell NBC: "This is just another desperate attempt by Ken Calvert because he cannot run on his 30-plus-year record in office." Calvert's response: "She tried to censure the president. She said he needed to be punished. She spent 10 years running away from him."

The play here is simple. California Republican strategist Dave Gilliard told NBC: "Calvert's best play is to get into a runoff with a Democrat, and then this race is over on June 2." Democrats don't need to win this seat. They just needed to make it cost something.