'Ear this, America: A uniquely unscientific poll of Iowa voters suggests Joe Biden is struggling to maintain his front-runner status in the Democratic presidential primary race. Just 24% of Iowa State Fair goers “voted” for Biden by dropping a kernel of corn in his jar in a fair display designed to predict the winner of the nominating contest. The vice president out-husked his closest rival, Pete Buttigieg, who drew 16% in the Cast Your Kernel contest. Sen. Elizabeth Warren was right behind with 15% and Sen. Kamala Harris took 11%. That margin reflects a closer contest than most national polls,...