We’re not supposed to eat meat on Fridays during Lent.  However, yesterday was the Solemnity of the Annunciation, which means the rule of abstaining from meat was suspended for the day.

Whether Biden knew of the suspension, we cannot know.  Even if he didn’t, this would have been a small transgression (especially compared with his full-throated support for killing unborn babies).  It may even have been excused by the likelihood that he genuinely forgot the date, the liturgical season, or the rule.