The ad buy, which will focus on the senator’s vote to confirm Justice Brett M. Kavanaugh, is the largest investment from Planned Parenthood Votes in any state this cycle.
The intended parents had asked to end the pregnancy at 20 weeks when the fetus was diagnosed with a life-threatening condition, setting off a painful legal battle.
Democratic Lt. Gov. Peggy Flanagan and Republican Michele Tafoya are running for Senate, while Sen. Amy Klobuchar (D) and state House Speaker Lisa Demuth are running for governor.
Arizona Gov. Katie Hobbs (D), facing a tough reelection fight, chose former mayor John Giles, a lifelong Republican who recently became an independent.
Democrats are ahead in polls, and voters typically punish the party that controls the White House during midterms. But Republicans have several paths to maintaining power.