These "jokes" are already getting incredibly stale and silly. I don't get it at all. A provider is not just going to let you come in, even with say a billion USD, and buy X individual's data. That's not how it would work at all, this is not just like some sort of self-checkout to get someone's data.
And even if it was remotely like that, I can guarantee you that the providers will go to lengths to make sure they didn't just lobby millions (speculating, of course) to get this through and then throw the same congress members under the bus that they lobbied to and then hand out their data to get them in trouble with the public.
However, they can do what everyone else does; buy anonymized data for the area person X lives in. They can then use countless techniques (that have been demonstrated repeatedly) to de-anonymize the data and find out about person X.
What I'm getting at is even if they did try to use the method you described, I highly doubt they would even include that data of those congress members. I bet they blacklist users in situations like this. They are not just going to give that sort of thing out via a sell. Even if they law ALLOWS them, doesn't mean they sell to anyone with money.
All-in-all, I think if you donate any money towards these crowdfunding initiatives, you might as well burn that money because it's not going to get people the info they think they are going to get. ¯\_(ツ)_/¯
Now you are being over-optimistic about ISPs' sophistication. If I wanted data to target white renters, I can get it as long as I don't do it wearing a klan hood. A data set encompassing legislators is for the most part a data set of lawyers with some special characteristics. It could be a subset of data you can buy, or it could be assembled as a mosaic.
And even if it was remotely like that, I can guarantee you that the providers will go to lengths to make sure they didn't just lobby millions (speculating, of course) to get this through and then throw the same congress members under the bus that they lobbied to and then hand out their data to get them in trouble with the public.