"you father the child you pay for the child" that has predated the US legal system.
Even the presumption of a "child born during wedlock is the husband's" is based on that assumption. (from preDNA days).
The rules for NOT paying just because some fiction of a sperm donor is the new "thing". The sperm donation contract is contrary to the establish legislative and common law (and even civil code) of support belongs to the child.
This is not a left concept, it is about supporting the next generation. It is the left that seeks to break any links other than those that involve all pay government for redistribution to each according to their needs.
No, you don’t “pay for the child” after anonymous sperm donation, for better or for worse, at least not until this activist judge said so. I don’t consider tens of thousands of standing contracts after almost 50 years to be “a new thing”.