Your donation records to the fec are explicitly not allowed to be used for donors mining like this. I'm sure it still happens, but it's not the majority.

What happens is that the campaign you donate to to puts you on their list (allowed) and then shares that list with others in the party (also allowed). They share back and forth so fast you can't get out of it.

This is why it's the email that's shared not the name. FEC records don't have your email attached to to them, but the spam still follows unique emails like "[email protected]".