Spanish elections and politics

[Dereich]

It is hard to argue for Rajoy to go since this is the third election in a row where he led PP to be the largest party in terms of seats and votes.

In the most recent poll I could find, Rajoy's net approval rating was -44. He has presided over a large number of corruption scandals. He's even been declared persona non grata by his hometown legislature. No leader with an ounce of sense will ever agree to join him in government. C's, especially, would suffer with the voters who chose them as an alternative to PP and PSOE corruption and aren't willing to support PODEMOS radicalism.

[Dereich]

It seems that if there is a third election this winter and the PSOE is in the shape it is in today the PP should emerge with a majority by itself and Podemos  would become the main Leftist opposition party.  PSOE would be wise to make a deal with PP while there is till or else their leverage will go down from here.

How would tying themselves to one of the most corrupt and disliked governments in the Western world make PSOE more likely to retain their status as the main Leftist opposition? We have the example of PASOK who suffered for doing exactly what you're proposing to point to the contrary.