On January 13, former Louisiana Governor Edwin Edwards was released from federal prison. See this story. Edwards is the person who invented the “top-two” election system. He not only persuaded the Louisiana legislature to pass the idea in 1975; he also carried on a high-powered campaign to persuade the U.S. Justice Department, Voting Rights Section, to approve the idea. The Department had previously rejected the idea when Mississippi had passed it.
Edwards believed the top-two system would make it easier for conservative Democrats to continue to win elections in Louisiana. Louisiana has been using that system for state and local elections for the past 35 years. Louisiana used it for congressional elections between 1978 and 2006, and during those years, no incumbent member of either House of Congress was ever defeated for re-election (except in 1992 when, because of redistricting, incumbents had to run against each other). Washington state started using the top-two system in 2008, and no incumbent member of Congress from that state has been defeated for re-election either, since top-two has been in effect.