The Blue Slip is a century-old Senate tradition that's blocking Trump's judicial appointments—and most Americans have never heard of it. Alina Habba just resigned as New Jersey U.S. Attorney after Democrat senators used Blue Slips to kill her confirmation. Trump says 7 prosecutors are in jeopardy. But here's the shocking part: this "tradition" was weaponized in 1956 by segregationist Senator James Eastland to block pro-civil rights judges. Now GOP Senators Grassley and Thune are defending it.