EU immigration policies have incrementally evolved from a purely intergovernmental to a deeply integrated EU policy area. In practice, EU immigration policies and EU secondary legislation still leave significant discretion to the Member States, as witnessed by key developments in the various subfields of immigration policies—including policies on border protection, return and irregular migration, as well as labor migration and family migration policies. The key academic debates on EU immigration policies have mainly focused on explaining the decision-making processes behind the adoption of EU policies as well as their impact on national policies. While scholars find that these EU policies have led to liberalizations in the areas of family migration or labor migration, the irregular migration and border policies of the EU have gradually produced more restrictive outcomes. Policy liberalizations are usually based on the impact of EU institutions, which tend to have more liberal positions than Member States. Lowest common denominator output at the EU level, such as on the Blue Card Directive, is usually due to a resistance of individual Member States. With deeper integration of the policy area over time and qualified majority voting, however, resistant minorities have been increasingly outvoted. The stronger politicization of some areas of immigration, such as family migration, has also led the European Commission to curb its legislative proposals, as it would be much harder to adopt a piece of legislation today (2019) that provides adequate protection standards.