In the same way the Republicans have locked up 46% of the US voters, PiS has managed to harden its base to 34% of the electorate come hell or high water.
The party fragmentation makes rooting out PiS from power nearly impossible, except if:
- Konfederacija start eating into PiS margins
- Lewica leadership considers a merger with PO under a new name
Which is likelier?
The most likely scenario:
New Left joins KO (coalition of PO and minor parties) as minor member or merge with iPL, which is leftist party in KO. I don't think New Left is important enough to change name of coalition, when they join. After merger of KO and New Left, Left Together will be the only leftist party, which is independent from KO. They would focused on economic left issues.
I can't exclude the first scenario, because PiS victory in local election was pretty pyrrhic and their leadership will likely draw wrong conclusions.
The turnout structure was very favorable to PiS. Turnout in cities and among youth was terrible low. With normal turnout structure, which is more likely to happen in European election, PiS would finish with less than 25%. The good result of PiS in Sejmik election was caused by increased polarisation. PSL lost almost all of national-PiS and local-PSL voters, which was seen as PiS gains in Holy Cross and Lublin voivodeships.