This all such bs and propaganda I hardly have the energy.

Abortion doesn't "not matter" to the left, so your question is moot. There's a variety of opinion on abortion on the left but (obviously) agreement that abortion should remain legal.

Catholic social teaching should matter to Christians on the right because it's a foundation of the gospel. Sometimes I wonder if you guys even read the gospel. It's radical. It's stinging in its criticism of exploitation and hypocrisy, particularly by the powerful. There's a reason for this: the peasantry was getting crushed by the Romans and their Hasmonean collaborators. The Jesus movement arose among the poor and was highly concerned with justice for the poor. It's a prominent feature of the gospel. If you don't like it, maybe Christianity isn't the religion for you.

And by the way, nobody is forcing you into a gay marriage. I'm amazed by the  hostility toward a tiny minority who merely demand the same rights as every other citizen. Move on!