The Survival of Democracy in Central and Eastern Europe

And in Hungary's local elections, the opposition retook power in Budapest and won mayoral races in 10 other cities.

The question now is whether these results augur a broader political shift in the region.

The PiS's retention of power in the Sejm — the lower and more powerful chamber of Poland's parliament — is undeniably a significant success. But the party's strongman leader, Jaroslaw Kaczynski, was clearly expecting a better result.

The PiS's loss of the Senate means that it can no longer ram through controversial legislation without any real debate (though its 235 votes in the Sejm will still allow it to override Senate vetoes).

The Polish opposition now has a chance to prove itself. Overall, opposition parties received 900,000 more votes than PiS's combined total.

The Polish opposition now has a chance to prove itself. Overall, opposition parties received 900,000 more votes than PiS's combined total.

That means a narrow majority of the electorate is on the opposition's side, and could deliver a victory for a common opposition candidate in the presidential election next spring.

There is no obvious choice for that role, however. Donald Tusk, the outgoing European Parliament President who formerly served as Poland's Prime Minister, has been all but forgotten, judging by his weak showing in opinion polls. Nonetheless, the opposition still has time to get organised.

The largest opposition party, Civic Platform (PO), maintained its previous level of support, running as part of the Civic Coalition, which won 27.2 per cent of the vote.

But PO's leader, Grzegorz Schetyna, fared poorly in Wroclaw, and remains one of the country's least popular and most criticized politicians. Many want him to...