Once they completed the Coronavirus test on President Trump.....it put both Bernie and Joe in a harsh position. Sometime in the next week....they both need to do a public gimmick and take the 'challenge'.
If either come up positive? Well....for Bernie, it doesn't matter....his election chances are rapidly declining. If Joe came up positive? He'd have to sideline his campaign for 14-plus days, and Bernie would gain.
If both decline? I think that is the outcome....just pretend that Trump's episode doesn't affect them.