Democrats are finally alive to the threat of Robert F. Kennedy Jr.—and it’s about time. They worry not only that the gadfly might pull crucial votes away from Joe Biden. They worry more that Republicans will help make that happen—by running the same playbook Democrats honed in GOP primaries. And why not? All’s fair in love and meddling.
Mr. Kennedy’s announcement this week of a running mate—tech entrepreneur Nicole Shanahan—was met with louder-than-usual howls of “Spoiler!” The Democratic National Committee is assembling a team dedicated to the destruction of Mr. Kennedy and other third-party candidates, led by veteran strategist Mary Beth Cahill. Left-wing groups are already working to block Mr. Kennedy from the ballot in key swing states, rolling out liberal legal titan Marc Elias to file complaints of campaign irregularities.