Former U.S. President and Republican presidential candidate Donald Trump speaks at a campaign event in Council Bluffs, Iowa, U.S., July 7, 2023. REUTERS/Scott Morgan/File Photo WASHINGTON, Aug 2 (Reuters) - Efforts to hold Donald Trump criminally responsible for attempting to overturn the 2020 election were gaining steam, as the former U.S. president prepared to face federal charges in a Washington courtroom on Thursday while Georgia state prosecutors looked poised to issue their own charges in the coming weeks. Trump - the front-runner for the 2024 Republican presidential nomination - was indicted on Tuesday on four counts, including conspiring to defraud...