VoteOften is a social news site like Digg but with additional features that set it apart. In addition to user-submitted stories, the site algorithmically pulls in the top political stories from several reputable news sources. Stories are not only voted up or down but rated for their liberal or conversative bias as well. They are also tagged as relevant to particular candidates or issues, so you can view all stories related to, say, Barack Obama or national security.
More advanced features include the ability to rate candidates based on how they are portrayed by a particular story. You can indicate whether you got a good or bad impression of the candidates mentioned in a story, and the site will generate a bar graph showing how everyone felt about the candidates in aggregate.
Since this site just launched, the homepage stories are not terribly fresh yet; this will hopefully change once site activity increases. Check it out, participate, and go vote.