Judges bend over backwards to avoid any sniff of impropriety or conflict. See attached.
But to dumb it down for you, let’s imagine a loved one is on trial for assaulting a police officer. Would you consider it a conflict of interest (or appearance of) if the assigned trial judge is married to a police officer from the same police department as the injured officer?
Link: https://www.uscourts.gov/sites/default/files/code_of_conduct_for_united_states_judges_effective_march_12_2019.pdf