In these times of elections, the question was raised by @scaaahu of what happens when no moderator is available, typically at certain time intervals: if all moderators live in the same timezone, then they might share the same unavailability. In addition, academics might need to travel often, and it could be the case that for a few days, 1 or 2 moderators only are available.
Many moderating operations are not particularly urgent, but some are, in particular deleting spam or intervening against vandalism. Could it be possible, if mods can declare their unavailability, to increase the privileges of high rep users if needs be? For instance, if I know I won't have time during one week, I could easily set it up on the site, so that it is certain that I won't be able to act as a moderator during that time. In the worst case scenario, if all mods are unavailable, then users with high-rep should be able to act as moderators (suspending spammers and vandals, removing/hiding offensive content, etc).