2013 Elections in Germany

[Hnv1]

This NRW poll (Left at just 3%), would actually mean that the Left is below the 5% treshold Germany-wide if we assume the same uniform losses in other states.

In 2009, the Left got 8.4% in NRW, but 11.9% Germany-wide.

So, the Left did 42% better in Germany than in NRW.

With 3% right now, the left would get ca. 4.3% Germany-wide.

As someone who does not track German politics is there a reasonable explanation for Die Linke's crash in popularity?