Now that the dust has settled after the first and perhaps only presidential debate between Vice President Kamala Harris and former President Donald Trump, the state of the polling looks clear: Harris has a slight edge in a race that remains extremely close. Harris leads national polls, on average, by 2 or 3 percentage points. More importantly, she leads in the key Electoral College states of Michigan, Wisconsin, and Pennsylvania by 1 to 2 points in recent polling averages. And if...