Unions, universities, corporations, banks, churches, nonprofits, etc. etc. Maybe we should celebrate Mancur Olson Day instead of Labor Day or Memorial Day or Independence Day or any of the other Days from which we seem to draw absolutely no lessons for our current politics whatsoever.
One phrase jumped out: "focused on protecting existing members rather than bringing in new members". If there is no growth in unions, it's certain that they can't protect anyone. Get back to the idea that the effect of many people can protect the rights better than any effort to protect a few.