A mayors' council is formed to "Dismantle the systemic racism in this country". A worthy goal but impossible. Why?

It is impossible.  Everybody has a little racist inside of them (anyone who says they don't is only lying to themselves).  Most of us repress and subdue it, but every once in a while it tries to rear its ugly head.  It's up to each individual to make sure it "never sees the light of day".  Sadly, many people don't subdue it.  Instead, they feed it, allowing it to grow and permeate them with its deadly poison.  Then they encourage others to allow theirs grow as well.  And the poison spreads.  It's much easier to stop a single seed from sprouting, than it is to uproot a full grown plant.  Once a person is consumed by racism, it's extremely hard to eradicate it (but not impossible).  Nobody can change another person.  No council, committee, or law, can change a person - no matter how hard they try.  Only that person can change themselves.