MSNBC's Ari Melber hosts "The Beat" on Wednesday, April 3rd, and reports on Bernie Sanders campaigning alongside President Biden, special counsel Jack Smith's latest filing, and Donald Trump's legal battles. James Carville and Lisa Rubin join for the latest fallback installment. Plus, hear Ari Melber's interview with Bush White House vet Karl Rove. David Plouffe and Erin Haines also join.