It remains to be seen whether or not President Biden remains the Democrats’ nominee for president, amid growing calls to replace him atop the ticket. But at this moment, the race is frozen in place. Indeed, Donald Trump’s lead in national polling — now sitting at 3 points (47 percent to 44 percent) per the RealClearPolitics polling average — has remained remarkably consistent for months. This is true even after Biden’s disastrous debate performance and the discontent it engendered among Democrats. Since last November, the race has been stubbornly rangebound, with Trump’s lead over Biden consistently within a 1 to...