AfD won in a marginal state and it's a very, very long way for them to win federal elections in Germany.

The AfD is polling ~30% for federal elections[1]. The NSDAP had 18.3% in 1930[2], 37.3% in 1932[3], 33.1% in 1932[4] and 43.9% in 1933[5] (and 9x% ever after).

Yes they are still away from having the absolute majority, but please don't undersell the issue. They have a 10% difference from the second place.

    [1]    https://dawum.de/
    [2]    https://en.wikipedia.org/wiki/1930_German_federal_election
    [3]    https://en.wikipedia.org/wiki/July_1932_German_federal_election
    [4]    https://en.wikipedia.org/wiki/November_1932_German_federal_election
    [5]    https://en.wikipedia.org/wiki/March_1933_German_federal_election