2000 Chevy Blazer One wiper stopped wiping

One wiper stopped wiping (driver's side front wiper, that is), worked one day, not the next, then the next day worked, and since then, nothing. The other blade angrily attacks the broken blade with each pass, as the weaker blade sometimes rises up just a bit, just to be immediately smacked back down again. Kind of like the angry mob of geese at Hermann Park who mangled the back of the neck of an unfortunate, sickly looking goose as I and my young daughters looked on in horror. But more like a robot battle, with one robot obviously in the wrong weight class, but with rainwater instead of blood. You see now why I have chosen not to insert a photo. It's total mayhem out here.