True, but they were punished in the 2009 for the grand coalition, and I doubt their voters are in it for another one.
Depends of the voter. The socialist, left-leaning voter was angry, but the centrist one probably liked the CDU-SPD government.
I would assume that a centrist voter who liked the grand coalition would vote CDU rather than SPD.
But that depends on so many factors, and in any given election there are going to be a lot of swing voters between CDU and SPD. Furthermore, if the situation stays like this, with grand coalition seemingly inevitable and Union parties with a comfortable marging of 6-12 points over SPD, some more tactically minded centrist voters could even decide to strengthen SPD instead of Union.
Newest poll from Forschungsgruppe Wahlen shows CDU/CSU at 38%, SPD 29%, Greens 14% and Linke 7%, while FDP, Pirates and all others each have 4%. So SPD-Greens would have no majority with 43 against 45, and grand coalition again emerges as the only possibility.
What I find remarkable is that currently all six national polling institutes have both FDP and Pirates at 4%, each and every of them. Guess that kind of agreement between all institutes has to represent both parties' actual support well.
