Hoisted from the comments elsewhere:

According to various officials, there are 11,000 to 15,000 Americans in Afghanistan. Several days into the airlift, with all our C-17's and KC-135's in operation, we only managed to fly out 165 Americans in a single day. At that rate it would take 66 to 90 days to evacuate all the Americans, which would be Oct 23 to November 16th. The Taliban will shut the operation down long before then, probably by Sept 11th. Many of those Americans will simply disappear.

After the fall of Saigon, American's spent decades wondering if Nixon and Ford left POW's behind. Biden will be accurately blamed for willfully abandoning American civilians on the battlefield, all because he wanted some zinger lines for a speech. He will be condemned now, he will be condemned tomorrow, and he will be condemned forever. Twenty years from now people will still talk about Americans who were abandoned and might still be living as a captive in some village outside Herat or Kandahar.