26 German Election 2021—what happened?

“Just because you do not take an interest in politics doesn’t mean politics won’t take an interest in you.”
— Pericles

Background Angela Merkel was Chancellor of Germany from 2005 to 2021. The election in Autumn 2021 could be said to be the first of a new era in German politics.

Questions Which parties did well in the 2021 election? Are there geographical patterns in party support? What structural factors are linked to party support? Are Erststimmen (votes for candidates) and Zweitstimmen (votes for parties) closely related?

Sources The Bundeswahlleiter (Federal Returning Officer) has a website (Bundesamt (2021)) offering detailed election results in various forms, a dataset of demographic and structural data for each constituency, and maps of the constituencies. UK election data is available in the R package parlitools.

Structure There were 299 constituencies in 16 Bundesländer (states), just over 61 million registered voters, almost 200 smaller parties or groups standing in one or more constituencies, and 7 larger parties each getting over 2 million votes.