A lack of empathy is not a moral failing.
Some neurodivergent people feel low or no empathy towards other people. This is not an indication of moral bankruptcy or a sign someone is a bad person. You need to stop saying things like "Conservatives are evil because they just lack empathy.", or "The left is the party of empathy."
The word you are looking for is compassion.
Empathy is a feeling in which the suffering of others causes you to suffer to some extent.
Compassion is a conviction to do good for your fellow human beings because you feel their suffering should be alleviated.
The correct statement would be "Right-wing politics lack compassion." And the inverse "Leftist ideals are built on compassion."
We as leftists should not assume those incapable of feeling a certain emotion are incapable of acting with compassion, as that is deeply ableist.
The feeling of empathy can motivate compassion, but it is not required for a person to be compassionate. Those with low or no empathy can and do act with compassion. To care for others even in the absence of an instinctual pack-bonding drive to do so is truly revolutionary, and it should be recognized as such.