Social norms guide humans’ everyday behavior, and previous research has shown that social norms consistently predict some forms of political participation. Failure to conform to norms may lead to deviation and possible rejection, which humans innately seek to avoid since it threatens their need for belongingness. Following an episode of rejection, individuals are therefore likely to become increasingly willing to conform to norms in order to re-establish a position in their social group. In an experiment, we show that 1) individuals conform to a perceived political engagement norm, and that 2) when rejection associations are made salient, they become increasingly willing to conform to a political engagement norm. We also show 3) that this effect is moderated by individual-level need for belongingness, such that rejection primed participants with a high need to belong, showed the highest levels of conformity to the perceived political engagement norm. The results imply that social pressure is a strong motivating factor in political engagement, which is an important result suggesting that basic social affiliation needs may in fact have an impact on politics and political outcomes.