Sore loser law
In United States politics, a sore loser law is a law prohibiting the loser in a primary election from then running as an independent or representing another political party in the general election, thus basically blocking them from appearing on the general election ballot (though sometimes they may still run as a write-in candidate). Some states accomplish the same goal by having simultaneous registration dates for the primary and the general election, while other states ban the practice by preventing candidates from cross-filing for multiple parties, or by having laws that explicitly ban the practice.