The Democratic primary next week in Michigan’s 11th District could end a four-decade Jewish political dynasty — and spending by the country’s biggest pro-Israel lobby is playing a significant role. Because of redistricting, the race pits two incumbent Democrats against each other: Rep. Andy Levin, a Jewish Democrat who favors conditioning aid to Israel and counts some of Congress’ most outspoken Israel critics as his friends, and Rep. Haley Stevens, a non-Jewish centrist whose Israel commitments lie mainly in assuring its military security. Stevens has been the recipient of millions of dollars in outside funding far from United Democracy Project,...