RP simply could not go into a coalition with PiS: their electorate would never forgive them and never vote for them again.
Exactly. When you consider that almost every single government in Poland has enjoyed the support of "liberals" in some way - there is mathematically no chance of PiS gaining power.
More like 50.1%.
Well - not quite - because of the 5% rule needed to obtain parliamentary representation, 45% of the vote could be enough to get them 50% of the seats. But I'd say that 47-48% would be more likely. It's absolutely unprecedented in the 3rd Republic - even PO in the 2007 landslide only managed 41% despite the weak opposition.
The constructive no-confidence vote being proposed by PiS might succeed because it enjoys the support of Palikot and SLD, but only if some PO members abstained, voted for the measure* or called in sick.
Let's not forget that in Poland, as in Germany - to remove the Prime Minister in a constructive vote of no-confidence requires that an alternative candidate is proposed and voted in through a vote of confidence. The Prime Minister cannot be removed unless his successor is in place - which more or less guarantees that RP and PiS will never see eye to eye. It's also in RP's interest to keep PO in power - hence any candidate must be one which can push through issues important to RP. Ruch Palikota have also made it very clear that they only require three things from PO in order to give them parliamentary support. Let's also not forget that RP voters would never forgive Palikot if he removed Tusk in favour of a "PiS" man.
For instance if in the 2015 election both PiS and PO got 32% and SP got 15% that would constitute a PiS-SP coaliton of 47% and those two parties could form a government .
Except that SP are nowhere politically and their leader isn't even in the Sejm, not to mention that the only vote that SP get is stealing it from PiS - they have no new ideas.
I wonder just how tight a grip JK has on the party. Before now and the election (relative) moderates within PiS might wake up to the fact that he is nothing but an anachronism and a liability and get rid of him. As it stands, PiS is destined to remain howling from the periphery until he's gone anyway.
I wonder too - but then, he's still in power despite numerous electoral disasters. I've had it explained to me by one political scientist that he managed to remove almost every single credible challenger in the party. There is no-one left to challenge him - unless Ziobro manages to persuade a significant amount of them to kick out Kaczynski and bring in Ziobro.
Either way, 2014 and 2015 look like being yet more electoral disasters for PiS.