Strictly speaking if you are going to be an Anglican you have to believe in a Theocratic Monarchy however these days only converts to Anglicanism from Presbyterianism take this seriously (I used to take it very seriously). Presbyterianism tends towards Theocratic Republicanism (Richard Cameron, the "Lion of the Covenant" was a Republican) and there have been various plans of varying degrees of wackiness drawn up over the years for a Calvinist Republic of Ulster. Catholicism doesn't exactly bless one form of government over another but generally prefers Monarchy (I would highly recommend St Thomas Aquinas's and Dante's writing on the subject), however this is not the case in Ireland where outside of SSPX most Catholics are in love with Political Liberalism. You though have some Catholic Traditionalists such as my mum in law and Bishop Richard Williamson who are opposed to Democracy per se. The Russian student I have befriended here believes that Democracy is incompatible with the concept of Revelation. If things have been Revealed by God that makes True and Just no matter what the fickle masses think. Also I'm not sure than anyone with strong principles be they Socialist or Libertarian ones can be a good Democrat.