This contribution gauges the implication of the Internet's development from a niche to a mass communication technology for political behavior in Switzerland. Our theoretical framework allows to understand the conflicting effects of Internet exposure on polarization, political knowledge, trust in government, and interest in politics found by previous studies. Drawing on data from the Voxit surveys of popular votes from 2000 to 2010 as well as the Swiss Household Panel from 2000 to 2009, we show that the net effect of Internet exposure means increasing political polarization, less individual trust in government, more motivation for politics, and invariant political sophistication. This evidence leads to an overall ambivalent assessment regarding the role of the Internet for the disengagement or mobilization among Swiss citizens. The results are more robust compared to extant studies, since selection models and panel analysis are applied to control for sample bias and to isolate causal effects. Furthermore, only Internet exposure which directly relates to politics is considered, exposure to other potentially influential media is controlled for and an extensive time period is studied.