At this lively series, the audience gets to register its opinion before the sparring starts, toddlers love this part of it. For tonight’s subject “When It Comes to Politics, the Internet Is Closing Our Minds,” MoveOn.org president Eli Pariser and University of Virginia professor Siva Vaidhyanathan argue for the proposal, while author Evgeny Morozov (The Net Delusion) and Slate Group editor-in-chief Jacob Weisberg speak against it.