Does the willingness of mainstream media to provide platforms to radical actors radicalize citizens, or are media platforms just reflecting the increasing radicalization of the electorate? Existing research on the media's potential role in affecting audiences' political beliefs is inconclusive. While some studies show that media coverage increases the electoral appeal of far-right actors, other suggest that it can undermine support or lead to polarisation. Our study tests competing theoretical expectations about whether exposure to radical right views should increase or decrease support for these views via a survey experiment (N=3000), which we plan to field in Australia. Employing a 2x2 factorial design, the experiment uses a recent audio recording from a mainstream Australian network's interview with a far-right activist to test if exposing subjects to the audio legitimizes the activist's views, and whether the platform confers legitimacy. The first experimental arm varies whether subjects are exposed to the audio of the interview or to a weather report, and the second arm varies whether the network which broadcast the interview/forecast is mainstream (Sky News) or extreme (Youtube Channel). In this paper, we outline the research design, and perform design diagnostics. We hope that this experiment will be able to contribute to our understanding of the media's role in legitimizing radical views.