Political parties vary in their responses to electoral challenges, including the rise of populist competitors. To address these challenges, they sometimes engage with peripheral issues located outside their ideological comfort zones, and at other times they adhere more closely to their core policies. Although these patterns are well-documented, voters' perceptions thereof remain under-examined. This article argues that voters evaluate parties' claims not just based on the direction of their policy engagement – positive or negative – but also based on the commitment behind these actions, distinguishing ideological commitment from strategic manoeuvres. Employing a pre-registered vignette experiment, the article shows that voters differentiate responses to core versus peripheral issues, regardless of their personal agreement with the policies. Populist attitudes further moderate these perceptions, as voters with such views are typically more sceptical of parties' motives, limiting the impact of party behaviour on perceived commitment primarily to non-populist individuals. This highlights the importance of perceived commitment in elections and the constraints parties face in responding to competition.