Impossible. Your own biases consciously or sub-consciously would ultimately skew the curation. Facebook ran into this issue a little while ago with trending topics. If they did it manually, it was skewed. If they did in algorithmically, it was skewed based on whoever wrote the algorithm. The only possible way that I could see this working is if you had 3 columns: Left-wing, right-wing, and relatively unbiased (all news articles are biased simply because editors and news agencies are biased). Within those three columns, you place news articles in the left-wing or right-wing columns, and allow for voting (left, right, unbiased). However, this would also require you to have a large group from both sides voting in order to function properly. Good luck!