There are two targeting objectives for an election campaign: mobilizing core voters and chasing undecided voters. According to most previous research, negative campaigning exclusively fulfils a chasing function; parties use it to convince swing voters. The article argues that parties consider the mobilization of core voters as a second important function of negative campaigning. It is based on interviews with party campaign officials and a content analysis of election newspaper advertisements and press releases from the 2011 and 2015 Swiss National Council elections. The interviews and the analysis of parties’ attack behaviour show that parties use negative campaigning for mobilizing purposes, and in the analysed Swiss elections, it seems to be a more popular strategy than chasing.