Yes, the Third-way Social Democrats in the 1990s agreed to gold-bug- and neoliberal-inspired institutional structures in the Eurozone. They then proceeded in the 2000s to undermine the social safety nets and to ride the Eurozone credit bubbles. When the crisis hit they shared the right-wing diagnosis, they protected TPTB like the right-wing and then they got fully on board with the Austerity™ out of Seriousness™.

The successful left wing parties polling around 15% did none of this.

And you suggest the right strategy is to vote for the Social Democrats even if you agree with the left parties.

In addition, given a Social-democratic hegemonic party of the left and an also-ran party of the left, what vote percentage would you expect the also-ran to get? Assume the right/left split is 50/50 and assume the hegemonic party beats the also-ran 2:1 and you get the respective 30% - 15% vote shares.

On what basis you thumb your nose at the 15% of the also-ran calling it "not successful? Under European PR systems, that 15% translates into seats in parliament as opposed to zero representation in Anglo-American FPTP systems.

To err is of course human. But to mess things up spectacularly, we need an elite — Yanis Varoufakis