WASHINGTON, April 27 (Reuters) - West Virginia Governor Jim Justice launched his campaign on Thursday for the Republican nomination to challenge Democratic U.S. Senator Joe Manchin, a moderate who has been a constant thorn in his party's side. Justice, 72, has repeatedly changed parties, most recently in 2017 when he switched his registration to Republican after being elected as a Democrat in 2016. Manchin has been a key vote on every major piece of legislation of Biden's tenure, as a moderate representing an increasingly conservative state. Justice, a coal-mining billionaire, would first need to win a Republican primary against U.S. Representative Alex Mooney to become his party's nominee to challenge Manchin in 2024.

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