Saturday's shooting at the White House Correspondents' Association dinner has pushed Republicans to coalesce around President Trump's proposal for a new White House ballroom with a subterranean bunker . Why it matters: The $400 million ballroom would significantly alter the complex's structure and has drawn condemnation by preservationists and Democrats, who call it a vanity project backed by secretive donors seeking favor with the president. Driving the news: A suspect armed with a shotgun fired several rounds Saturday night at the Washington Hilton while trying to breach security. No Trump administration officials were injured, though acting Attorney General Todd Blanche told NBC's "Meet the Press" on Sunday they may have been the intended targets. The intrigue: At a news conference after the shooting, Trump renewed his push for the ballroom and underground bunker, a project judges have repeatedly halted and blocked.…