WHAT a sorry state Germany’s two big political blocs are in, a month before the election on September 22nd. In the 1970s more than 90% of West Germans voted for the two “people’s parties”: the “red” Social Democrats (SPD) and the “black” Christian Democrats (CDU) and their Bavarian sister party, the Christian Social Union. The difference was clear: red stood for unions and fairness, black for conservatives, business and the church. But the people have deserted the people’s parties. In the 2009 election, almost half the voters chose smaller competitors: chiefly the Greens, the Left and the Free Democrats (FDP). The blacks and reds have also lost members: the CDU 40% since unification in 1990, the SPD almost 50%. In a recent poll 69% of voters said they could not even tell the difference. It was an SPD-led government that pushed through labour-market reforms in 2003. The government of the CDU chancellor, Angela Merkel, has been inching leftward, ogling everything from rent controls to a minimum wage.

This week the SPD’s chairman, Sigmar Gabriel, sidled away from its most distinctive policy: higher income taxes and a wealth tax. They were “not sexy”, he said: a crackdown on evasion and avoidance might be better. His party’s leftists winced, but others detected a sign of willingness to form a grand coalition with the CDU, as in Mrs Merkel’s first term after 2005. She has declared herself open to the idea.

In a presidential system like America’s, her job would be safe. Fully 63% of Germans prefer her to Peer Steinbrück, the SPD’s candidate. But in Germany “popularity does not prevent you from being voted out,” gloats Jürgen Trittin, one of two leading Green candidates. In January a popular CDU premier was ejected in Lower Saxony, when its election gave opposition parties a majority of a single seat.

Mr Trittin, an ex-communist who wants to be finance minister, would love to see Mrs Merkel forced out of office in the same way. His party’s roots are in the 1970s’ counter-culture. The Greens first entered the Bundestag 30 years ago with a pacifist, anti-nuclear agenda. Awkwardly, they are now being reminded of other goals, such as decriminalising non-violent sex with children. An internal investigation is under way. On this, the anticlerical Greens may find some unusual sympathy with the scandal-strewn Catholic church.

But on most other fronts, the Greens have won. They are the only party in parliament to have gained members (44%) since unification. They have taught Germans their zealous recycling habits (brown glass in one container, green in another). Mrs Merkel’s most surprising U-turn, made after the Fukushima disaster in Japan in 2011, was to phase out all nuclear power plants by 2022.

Having, in effect, pinched the Greens’ energy policies, Mrs Merkel might now find it easier to form a coalition with them. That would be pleasant if it involved only the party’s pragmatic realo wing, strong in states like Baden-Württemberg. It would be much harder with Mr Trittin’s left-wing fundis. Their influence has made the Greens more radical than the SPD on such issues as redistribution.

Besides black-red (ie, CDU-SPD) and black-green, other coalitions, once thought improbable, are now possible. One is a “traffic light” of red, green and yellow—the colour of the FDP. The FDP is usually dismissed by the left as free-market fundamentalist, but Mr Gabriel’s tax musings may point to a softening. More radical would be a coalition of the three leftist parties, which between them may win nearly half the votes. That would bring in the Left, a party still seen as unfit for government by many, even in the SPD, because of its Communist roots. A prosecutor is investigating whether its parliamentary leader, Gregor Gysi, lied under oath about his ties to the East German Stasi (secret police). But he hints he might be open to a deal.