The extraordinary FBI raid on Rudy Giuliani’s New York apartment and office has sparked debate about what criminal charges Giuliani may face, and signals a widening criminal investigation into his Ukraine drive to help Trump in 2020 by sullying Joe Biden, former prosecutors say. The high-profile nature of the raid meant it required senior Department of Justice signoff, and underscored the investigation’s seriousness and progress. It also obtained several of Giuliani’s electronic devices and thus may have harvested a rich trove of new evidence and leads for investigators to follow.