The most striking and perhaps also the most important thing about the results of this week’s Spanish general election was something that did not happen. In defiance of some predictions, there was no populist uprising in Sunday’s poll, whether from the right, the left or the regions. Instead, the clear winner in a complex multi-party and regionally diverse contest characteristic of modern Spain was one of the two parties which have dominated the country since the return to democracy in the 1970s: the centre-left PSOE socialists of Pedro Sánchez.

The socialist victory was not absolute, but by recent standards it was clearcut. It will be keenly watched around Europe. It is a reminder that, in some parts of Europe, the social democratic centre-left retains the capacity, as it also currently does in countries as diverse as Finland and Portugal, to win elections by offering socially inclusive improvements to the status quo.

The socialists owe their success in large part to a spectacular collapse of Spain’s other big traditional party, the centre-right People’s party (PP). The PP took 45% of the vote in the 2011 election. On Sunday, it plummeted to 17%. Much of this collapse is explained by the ongoing and extensive Gürtel corruption case, which destroyed the PP government in 2018 and first brought Mr Sánchez to power.

Some of the space vacated by the PP on the right has now been seized by the ultra-nationalist and conservative Vox party, which took 10% this week. The Vox leader Santiago Abascal talks provocatively of a “reconquest” – a term with shameful anti-Muslim and antisemitic connotations. Nevertheless, it would not be sensible to treat the success of Vox as a decisive lurch to the far right in Spain, or a revival of Francoism. Reactionary Spain – staunchly Catholic, socially conservative and Castilian centralist – has always been a serious factor in the nation’s history, even after the death of Franco. It was always part of the PP coalition, but even added together the PP and Vox polled less strongly on Sunday than the PP did on its own in 2016. Sunday saw a redistribution of the rightwing vote in Spain, not an increase in it.

Mr Sánchez profited from a commitment to government programmes to get Spaniards back to work. They have helped give the socialist party a less technocratic appeal and ensured the support of Podemos, the radical post-crash party of the left, but without moving away from support for the EU and Nato. Podemos’s 14% score suggests that, for now, the balance of power between the two parties has shifted decisively in the socialists’ favour.

A crucial priority facing Mr Sánchez is to extricate Spain from the Catalan separatism crisis. On Sunday, voters in Catalonia notably failed to rally behind the region’s former leader Carles Puigdemont. Mr Sánchez, who backs more devolution, now has to juggle a new constitutional settlement with the outcome of trials of former Catalan leaders and the socialists’ need for Catalan support in parliament. The rewards, if he can pull all this off, could be immense. At least, after Sunday, the socialists have more political space in which to try a social democratic approach that many claimed was a thing of the past.