so maybe liberals have more conservative "friends" to de-"friend" than conservatives have liberal "friends" to de-"friend".
This is impossible as these are one-to-one relationships; for every liberal that has a conservative friend, that conservative has a liberal friend.
Can you explain what you mean by one-to-one? Most models of relationships are graphs, not functions. I am unsure what one-to-one means in this context. It does not appear that you mean each node may only have one mapping to another node, which would be, perhaps, the most sensible reading of a one-to-one relationship here.
In any case, node may be connected to any number of nodes, which means that a construct where you have six nodes, one self-identifies as "conservative" and five self-identify as "liberal". The "conservative" node may then be connected to each of the five "liberal" nodes. Is that one-to-one, by your usage?
It's more likely that liberals are the one's that initiate the un-friending.
Why?