I saw a podcast on this. SPD, which ruled North Rhine-Westphalia for 40 years from the 60s to the early 2000s, completely collapsed. There is evidence that the same thing is happening inn other SPD strongholds. That is surprising (at least to me) because I would have thought that AfD would take votes from the CDU, not SPD.
From the NRW city-council election (past weekend or two)...when you go line by line....CDU-SPD-Greens...all lost numbers going to AfD.
What AfD is campaigning upon...public-safety/crime ahead of migration.
I’ll say it (from the prospective that I’ve been around Germany off-and-on since 1978)...in the metro areas (Frankfurt, Hamburg, Koln,etc)...you need to pay attention to things, and avoid walking around after dark. In some cities...they’ve doubled the police force over a 40-year period, and it barely makes any difference.