One under-theorized aspect of "multiculturalism and the antidiscrimination principle" is religious and ethnicity based political parties. With political organization, the fact of pluralism is made concrete for democratic purposes. When the struggle for empowerment is "waged within the world of democratic politics" it is waged through parties. That is the associational form modern democracies have settled on for participation, representation, and governing, and for countervailing power and regular opposition. Particularist parties and bloc voting are key instruments of political conflict and, as important, of political integration. This Paper looks at the challenges these parties pose to democracy; specifically, at the principal reasons given for banning parties from participation in electoral politics. I identify four categories of justification for disqualification: violent overthrow, incitement to hate, altering the character of the nation, and outside support or control. This is a preliminary to setting out regulative principles of "defensive democracy."