>Is the list of doctors you visit private?

Yes, this is explicitly protected by law.

>I could probably discover such information

No you can't get this information, and certainly not legally.

>Your address is usually public

Exactly but I never "gave my consent to release my address," it just is.

>Birthday has never been publicly available until this voter data leak.

Open up a newspaper or open up yourlocalpaper.com There's a whole birth announcements section!

How do you think the RNC got this information in the first place? Public records. The RNC is NOT the government.