Global
@twiplomacy's world leaders list is a start but more importantly, they have a number of curated lists.
Every Politician has social links for politicians.
EU certainly have lists that could be used.
List of current heads of state and government/twitter-list - Archiveteam
North America
I can't find anything about open civic data, but I know they have curated lists for USA and Canada.Europe
EU certainly have lists that could be used.
Australia
Notes:
- I can't find anything about open civic data, but I know they have curated lists for USA and Canada.