Former South Carolina Governor Nikki Haley will kick off her campaign for the 2024 Republican presidential nomination this month, squaring off against her one-time boss, Donald Trump, two sources familiar with her plans said on Wednesday. The move would make her just the second declared Republican candidate and could set the stage for a more combative phase of the campaign, potentially putting her in the sights of the pugnacious former U.S. president. Haley's campaign sent an email to supporters on Wednesday inviting them to a Feb. 15 event in Charleston. There she will declare her candidacy, the sources said. South...