WASHINGTON (AP) - More than a million Internet users will be invited to vote in a virtual Democratic primary next week, but this most modern of elections is facing age-old allegations of vote-rigging. Howard Dean, who has built an extensive network of Internet-savvy supporters, is expected to get the most votes in the MoveOn.org primary. Organizers of the site say any advantage for the former Vermont governor is due to his appeal among their members, and not any misdeeds in their process or because one of their employees worked on his campaign. The primary begins Tuesday and voting runs for...