Focusing solely on Lafontaine is contraproductive when trying to assess the role of the Linke in a wider political context. Although I think that many people (most hypocritically the CDU/CSU) deliberately understood Lanfontaine that way, I acknowledge that he potentially could be understood as a xenophobe. But, anyway, the Linke is not Lafontaine. Have a look at the Linke's election manifesto:

In the case of the Linke, even disregarding our disagreement over the meaning of Lafontaine's statements, overemphais on personality is as much an obstacle to understanding party politics as in any case else. Even if he wanted to "adopt the neo-fascist line on integration", he would not succeed, because it is against everything the PDS, by far the bigger part of the Linke, stood for and stands for.