re: Why do liberals get so upset over abortion?

Their ideation of "freedom" is one that is falsely based upon a direct link with their own image of self-worth. This is all deeply rooted within virtue-signalling. "Hey, look at me, I stand in solidarity with those who stand for justice and freedom to express our views and do what we wish with our own bodies!"

As soon as a dissenting opinion is expressed, they interpret this as a directly personal attack on their own perverted sense of freedom and hence, self-worth. The most glaring piece missing here is that morality is nowhere a part of the equation.

This is why the progressives push so hard for relative morality - i.e. the absence of God (Evolutionary Theory as the framework), a moral law-giver. Because once objective morality is introduced, their dispositions entirely crumble at the foot of the judgement throne of God.