Can Mitt Romney pull a Bill Clinton? Can he go from generally disliked to well liked, all in a few months? His political fate may hinge on it. …

At this point, Mr. Romney is now minus six percentage points on the thermometer scale, meaning that 33% view him positively and 39% negatively—about where Mr. Clinton was going into the summer of 1992. …

But by late October 1992, just weeks before the election, Mr. Clinton had pulled off an extraordinary transformation. His favorable ratings had skyrocketed. Over half of Americans viewed him positively, while just over a third viewed him negatively. That’s pretty much where Mr. Obama stood in October 2008.