Democratic presidential front-runner Joe Biden is missing in action as the country struggles not only with the spread of the coronavirus but also its mounting economic fallout. With Sen. Bernie Sanders of Vermont quickly becoming an afterthought in the Democratic primary, the stage seems set for a Trump vs. Biden showdown in November. As President Donald Trump works diligently to guide a country in crisis — going as far as to hold daily White House news briefings — the former vice president’s media accessibility has been notably limited. His campaign has an explanation for that, however: ceilings! Biden’s campaign is...