By Alexandra Ulmer ATLANTA (Reuters) – Georgia Republicans on Tuesday dealt Donald Trump his biggest defeat so far in his bid to play kingmaker in this year’s U.S. midterm elections, choosing Governor Brian Kemp and Secretary of State Brad Raffensperger despite Trump’s efforts to oust them. The primary victories by Kemp and Raffensperger mark a major setback for the former president, who had waged a revenge campaign against them for refusing to overturn his 2020 election defeat, which he falsely claimed was the result of fraud. Kemp defeated former U.S. Senator David Perdue, who was backed by …