Advanced democracies have witnessed new types of political issues being represented and integrated in their party systems in the past decades. Yet, their patterns still remain unknown as to the conditions in which new political issues are first represented and eventually integrated in each party system. To fill this gap, this article illustrates such patterns through different phases of socio-economic transformation, party system responses to newly emerging issues, and electoral systems’ openness. By applying a ‘double-hurdle’ model, the article tries to elucidate the mechanisms in which new political issues are represented in the first hurdle and then integrated in party systems in the second hurdle. The analyses of new challenger parties across 15 West European democracies revealed that New Politics issues are represented through New Politics Parties (NPPs) when existing party systems are not responsive to the new issues but NPPs further grow and New Politics issues are integrated in party systems when existing party systems are more responsive to these newly emerging issues. Likewise, different conditions mattered differently for the representation and growth hurdles for both NPPs and Extreme Right Parties (ERPs).