Your confusion comes from misreading the motives of gun rights supporters. We aren't "reaching across the aisle" by defending their gun rights. By defending their rights, we are defending our own. We aren't trying to arm them. We are keeping the government from eventually disarming us.
It's no different than free speech "absolutionists" defending speech they find offensive. If there are "reasonable" limits, then they are no longer rights, but privileges. And privileges can be further eroded or taken away completely.
Your confusion comes from misreading the motives of gun rights supporters. We aren't "reaching across the aisle" by defending their gun rights. By defending their rights, we are defending our own. We aren't trying to arm them. We are keeping the government from eventually disarming us.
It's no different than free speech "absolutionists" defending speech they find offensive. If there are "reasonable" limits, then they are no longer rights, but privileges. And privileges can be further eroded or taken away completely.