Senegal is a multiparty democracy and freedom of association is respected. However, the PS has been in power since the 1950s, albeit under different names, and has spread its influence deep into the civil service, judiciary and local government, making opposition difficult. The main issue is the economy; the collapse of the AOF hit Senegal hard as it lost important markets, especially for Dakar's port. Other problems include the separatist movement in anti-Islamic Casamance, and discontent in the northeast, where drought and refugees from Mauritania are leading to tension.