How do masses react to party polarization? Limited effect of party polarization on mass polarization

Elite ideological polarization is rising in Western democracies. Is this elite ideological polarization associated with mass ideological polarization? I argue that when a party adopts a more extreme position, the masses polarize via two mechanisms. In-partisans should follow the party and adopt a more extreme ideological stance while out-partisans should backlash and move in the opposite direction. To test these expectations, I exploit a real-world sudden party polarization when the Labour Party of the United Kingdom suddenly shifted to the left under new leadership. Using British Election Study Internet Panel data, I find limited evidence that elite polarization leads to mass polarization. Overall, neither in-partisans followed the party, nor out-partisans backlashed to it. Only ideologically out-of-touch in-partisans adjusted their ideological stance to match their party, indicating the effectiveness of partisan cues, nonetheless. These findings provide insight into how the masses react to increasing party polarization, alleviating pundits' concerns that the masses are blind followers and bound to polarize if political parties polarize.