To me, this reads like you are attempting market timing without quite market timing. If that's the day that works for you, cool, but I think it is no better than your birthday or the day you adopted your dog or Pie day or any other single day (or that day every even year).
Your argument against quarterly rebalancing applies equally to any other day, and as for the election specific stuff, unless you have some special knowledge or prescience, you are just as like to rebalance in a way that loses you money as that gains. Just like any other day. As you said, you know something will happen. But that could by an up market, a down market, or a more or less the same market (and for days, weeks, months, or years), or any particular segment going up or down or staying the same, too.
Unless there is some historical data that says bonds almost always go up the day of/after an election, (or that they go down, or stocks go up, or down), knowing that some undetermined thing may happen isn't especially valuable. And if you are rebalancing to a specific asset allocation, that's even more the case. Because if you are low on bonds (for example) but you have reason to believe bonds will drop the day after the election, then you would either be buying against your own predictions, or not actually rebalancing on your designated day. (And of course, waiting until after your designated day then absolutely becomes market timing.)