Ask a surgeon how to deal with a medical problem and you are likely to get a recommendation for an operation. Ask a lawyer how you deal with a legal problem and you are likely to get a recommendation for a lawsuit. That’s the reflexive response here. It sounds as though you could bring a lawsuit and actually win it.

But what would you actually win? How many members care? It doesn’t sound as though you ever expected a lot of members to show up for meetings if the original quorum was only 10%. The board could call another meeting, before or after your case got to trial, get the 10% quorum and pass the amendment again under the proper procedures. Unless you are pretty sure you have to votes to reject the amendment, it is hardly worth the effort to start the suit.

If you have a general agreement among members that you should restore the old quorum requirement, you can check the bylaws or your state nonprofit corporation law to see how members can initiate a new bylaw amendment to restore the 10% requirement. Or threaten to call a special meeting to remove some of the directors who supported the change. If you don’t have the votes to throw the bums out at a recall meeting, maybe you have enough to elect new directors at the next election.

This looks like a legal question, but it is really a political one. Count the votes.

If you have the votes to restore the old rule, you have several options. If you don’t, you apparently have a good chance to win a lawsuit. That would be a potentially long and expensive battle. But even if you win the battle, without the votes, you will ultimately lose the war.