Common meaning:

Legitimate social institutions have the power to require people to comply with rules that align with their mission in society.

Hidden meaning of the Equity religion: 

Social institutions use power to force the marginalized to believe the abuse they are receiving from the dominant groups is normal.

Discussion:

Equity faithful believe the only purpose of current Western social institutions is to use power against the marginalized. Their purpose or goal is to convince the oppressed groups that the abuse that they are receiving is normal.

In the real world, there is no systemic power. It does not exist. It is an illusion created by the Equityists to try to convince those who have been overlooked that the reason that they don’t have what they want is because of some nefarious, systematic power that’s working against them.

The Equity believers claim there must be systematic power because the outcomes for members of two groups are different. The problem with this kind of thinking is that there can be many reasons for variations in group outcomes that have absolutely nothing to do with discrimination or bias.

If systemic power was actually real, there would be evidence. There is none.