Sen. Elizabeth Warren (D-Mass.) is putting newly confirmed Attorney General Jeff Sessions and Republican senators who approved him on notice. GOP lawmakers on Tuesday night invoked Rule 19, which forbids speaking ill of other senators, to silence Warren as she attempted to read a letter from Coretta Scott King criticizing Sessions. “She was warned. She was given an explanation,” Senate Majority Leader Mitch McConnell (R-Ky.) said. “Nevertheless, she persisted.” Less than 24 hours later, Warren fired off a blistering series of tweets noting that Sessions is no longer a senator ― and no longer protected by Rule 19. She also...