Are there two political factions here? Are those political differences significant enough that there is a valid difference in political identity? The Catholic Left and the Catholic Right are not readily identifiable with Democratic voters and Republican voters, and even a division between anti-Trump and pro-Trump is questionable, though those on the "Catholic Left" are perhaps more likely to be anti-Trump than the "Catholic Right" are pro-Trump, as many of the prominent members of the "Catholic Right" are critical of Trump when they think it is appropriate. Did he speak with his brother bishop
Wilton Gregory?
Maybe the bishop should explain what he means by the Catholic Left and the Catholic Right so we can determine whether he is lumping people under a label or not.
As for the Church avoiding being suckered into a secular, political agenda -- maybe the bishops should avoid politicizing themselves, but that's not a requirement of the laity. The problem is not the laity voicing their opinion, the problem is that bishops don't know what their appropriate role is (and canon law is wrong on this point). Before they say anything further, they should try to live in an actual community.