Reports - GIS, Policiation Boundaries, Address Validation
If your site has the Address Validation/GIS module, the Congressional District, State Legislature District Lower, and State Legislature District Upper data are all lookup subtables under Case Data.
If enabled, Census Tract is a lookup subtable under Case Data > Person > Primary Home Address > Address.
Other political boundaries on your site may also be under the Address subtable.
Not technically a part of GIS, your site may have lookup subtables under Case Data > Extended Matter Fields like "Borough" that are political boundaries in real life, but are set by users manually. As well, some sites add custom fields and lookups for boundaries; those live under Case Data > Custom Matter along with the other custom fields.