Earlier quoted context omitted.
There's an economics term for this, though I'm spacing on the name. It's the same reason the taxi lobby is so strong - it's a subset of 1 issue voters with concentrated financial support of key issues. It's also behind why tax loopholes are so hard to close - a small subset cares a lot, but the masses less so.
There are several. Smith noted Hobbes's truism: wealth is power. You might be thinking of the logic of collective action, Mancur Olsen.
https://en.wikipedia.org/wiki/The_Logic_of_Collective_Action