United Airlines’ chief executive officer said his company will mandate passengers to show proof of COVID-19 vaccination if President Joe Biden says so. Scott Kirby told CBS News’ “Face the Nation” on Sept. 19 that he would support such a mandate even though it would also cause inconvenience for vaccinated passengers. “I think the administration’s doing a really admirable job of trying to find all the levers to push to get the whole country vaccinated,” he said. “I think the administration’s perspective has been that getting people vaccinated at work, it’s a one-shot, and you can really get a high percentage of the country, as opposed to making it a burden on people that are vaccinated—every time you get on a plane, a train, any kind of public transportation—to prove that you’re vaccinated.” More than a week ago, Biden announced that he would direct the federal government to potentially impose …