It is haram or "legally forbidden by Islamic law" to participate in a democracy. Islam is first and the people follow. Human laws, such as an American Constitution, contradict Islam and its laws. Democracy will destroy itself from within. You can not work from within, from the perspective of a political party, because you would have to represent non-Muslims as well. The political process itself is haram. Muslims have to work outside the political process to advance Islam. Cf. especially after the 3:00 mark, interview with Dr. Abdul Wahid, Hizb ut-Tahrir in Britain interviewed about the hizb on the UK's Ummah Channel: 31 January 2010.