Left-wing rebels quit Italy’s Democratic Party this weekend to start a new party with remnants of the old left, called the Democrats and Progressives.

The group consists of leftwingers who are dissatisfied with the centrist leadership of Matteo Renzi, but they could end paving the way for an even less social democratic Italy.

Renzi, who was prime minister until December, is expected to be reelected as Democratic Party head in April. He intends to call early elections and return to the premiership at some point in 2017.

Enrico Rossi, the regional president of Tuscany, and Roberto Speranza, a lawmaker, could not stomach that prospect. They were supported in forming a new left-wing party by former prime minister Massimo D’Alema, a one-time communist, and Pier Luigi Bersani, Renzi’s left-wing predecessor as party secretary.

Disunited left

Last week, I cautioned Italy’s leftists against doing this.

A disunited left could allow the anti-establishment Five Star Movement, which is Euroskeptic and Russia-friendly, to win the next election.

Polls show that Rossi and Speranza could win between 4 and 6 percent support. That might be enough to prevent the Democrats under Renzi from placing first. He is polling neck and neck with the Five Stars.

Yesterday’s war

Left-wing purists are also fighting yesterday’s war.

They aren’t wrong that Renzi’s liberal reforms have scared away blue-collar and public-sector voters.

But such low-income voters, especially in the poorer south of Italy, have been defecting to the political right for years.

Renzi understands that the Five Star Movement, with its appeal to young, middle-class and urban voters, is his real competitor. Its voters don’t pine for a restoration of the welfare state; they want Italy to finally catch up, in economic and social terms, with the rest of Western Europe.