if my counting is right, then an Green-SPD-Linke coalition (
There is no majority for that....the Greens are stealing the voters from the former SPD...that means there isn't a growing but an exchange of voters.
Especially as the Green party is no longer considered "left". She could become the next bourgeois party for the better off, educated, towns people. They are mainly liberal but less social oriented. That would make for a big and influential but not a future people's party of the kind of the sinking SPD.
Additionally to that are the Greens a "western" party. Their support in the East is rarely more than in the one-digit scope.
There the AfD is kicking out the Greens and the "Linke"...
That all means it doesn't look good for a future left chancellor coalition.