Byron York: Democratic shakeout: Biden losing altitude, Harris surging, field dividing, bottom stuck at bottom

There have now been five national polls since the first Democratic presidential primary debate. Together, the surveys, conducted by ABC News/Washington Post, Quinnipiac, CNN, The Hill/Harris, and Politico/Morning Consult, show the debate has shaken up the race. The field has separated into three clearly definable tiers, all atop a large group at the bottom made up of candidates with virtually no support.

Within the first tier, Joe Biden, Bernie Sanders, Kamala Harris, and Elizabeth Warren, the leaders’ positions are rapidly shifting. Since the debate, only one of the four, Harris, is up, while Biden, Sanders, and Warren are down.