Drupal 7 - Add Items to multiple places in a menu
Unfortunately, this is a feature not available in Drupal core. The issue is being worked on, but does not currently have a solution: http://drupal.org/node/609542

In the meantime, one potential solution is to use path aliases to the same node. Thus you might have /voter/our-public-awareness-campaign and /news/our-public-awareness-campaign which both point at a particular node. Drupal should treat the two menu entries as unique/separate then, and thus only the one you want to show as the menu should be activated.