Why are Texas Democrats camped out in Washington?

Texas Democrats are camping out Washington to try to kill a Republican bill making it harder to vote in the Lone Star State. They’re using a rarely deployed tactic of a minority party trying to block legislation by depriving its rivals of a quorum. They used this same tactic in late May, walking off the floor for a couple of hours to kill a similar voting bill before a midnight deadline. But to kill this bill, Democrats will have to be gone far longer. History shows that’s tough to pull off.