The rise of the far right is increasingly raising the question of whether partisanship can have negative consequences for democracy. While issues such as partisan bias and affective polarization have been extensively researched, little is known about the relationship between identification with anti-system parties and diffuse system support. I address this gap by introducing a novel indicator and utilising the GESIS panel dataset, which tracks the rise of a new party, Alternative for Germany (AfD) from 2013, when the party was founded, to 2017, when the AfD, now transformed into a right-wing populist and anti-system party, entered the federal parliament for the first time. Employing a panel fixed effects design, I demonstrate that identification with Alternative for Germany reduces trust in the Federal Constitutional Court by a considerable margin. These findings are robust across various alternative specifications, suggesting that the effects of anti-system party identification should not be dismissed.