Crossover voting

Definition

Crossover voting happens when someone votes in a primary for a party they don't usually support. It's only possible where the rules allow it, in open or partially open primary states, since closed primaries require party registration to get that party's ballot.¹

Why it matters

Crossover voting can be sincere, a voter simply prefers the other party's candidate, or strategic "party raiding," where voters try to nominate the opponent's weakest candidate. Research on open-primary states like Wisconsin finds deliberate raiding rarely changes outcomes, even though the tactic draws outsized media attention every cycle.²

Seen in the wild

In the 2008 Democratic presidential primary, radio host Rush Limbaugh's "Operation Chaos" urged Republicans to cross over and vote for Hillary Clinton to prolong her contest against Barack Obama, a widely cited but modest-impact example of attempted party raiding.³

Related

• Closed primary
• Top-two primary
• Jungle primary
• Plurality

Sources

1. Ballotpedia, "Crossover voting," 2024. source ↩

2. Marquette University Law School Faculty Blog, "Crossover voting is uncommon, even in Wisconsin's wide-open primaries," 2023. source ↩

3. Newsweek, "coverage referencing 2008 'Operation Chaos' and 2024 crossover strategy discussion," 2024. source ↩