Tonight on The Last Word: Donald Trump remains the world's biggest threat amid global chaos. Also, a Trump whistleblower announces his run for Congress. Plus, the UN Security Council calls for Gaza humanitarian pauses. And a new MSNBC documentary, "Periodical," examines reproductive policies and culture. Joyce Vance, Ben Collins, Eugene Vindman, Noga Tarnopolsky, Nicholas Kristof, Madeleine Morales and Anusha Singh join Ali Velshi.