First, across all seven countries, the salience of immigration and integration was relatively low in 1995. It increased in the early 2000s and in most countries decreased somewhat in the late 2000s. Second, there are country-specific trends. Across countries, the issue is least salient in Ireland and Wallonia, and most in the Netherlands, Austria and Spain. All countries experience peaks of politicization at different points of time. Third, the debate has shifted from questions of immigration to questions of integration. Fourth, immigration is a more contested issue in certain countries than others. The United Kingdom displays the highest level of polarization over time, the German speaking part of Switzerland the lowest. There are substantial fluctuations over time, but countries where party politics is dominated by two large parties (UK and Spain) tend to be the most polarized. Surprisingly, the radical right parties are not the main claimant at the level of parties. This finding is particularly strong in Austria, and with reference to the Freedom Party (FPÖ). It is the mainstream parties that most frequently appear as claimants on the immigration issue. Fifth, salience and polarization of immigration and integration are not clearly related to the influx of immigrants, to the share of foreign-born residents, the policy responses, or the state of the economy. Sixth, country-specific factors affect polarization and salience of immigration. In all countries, politicization is a mixture of political leadership or initiative, and circumstances that provide opportunities to influence politics. In most countries politicization is driven by political parties (top-down), but in Ireland, the UK and to a lesser extent Switzerland, there is more room for civil society actors and journalists (bottom-up).