Here's a great way to visualize former Massachusetts Governor Mitt Romney's inability to inspire Republican primary voters: Imagine the candidate delivering a major speech at a pro football stadium. Now picture that instead of 65,000 cheering supporters, his actual audience is about 1,200 people seated quietly on the field directly in front of him. Unfortunately for Mr. Romney, no one needs to imagine that scenario. It's what actually happened today at Detroit's Ford Field. Instead of the major economic address promised by his campaign; the small audience was subjected to the same old policy ideas, quips and nervous laughter we've...