With just over a year to go till the US presidential elections, it remains to be seen which version of the Democratic party will challenge President Trump: the centrist party of Joe Biden and Pete Buttigieg, or the more radical party of Bernie Sanders and Elizabeth Warren? While the Republican party has tied its fate to President Trump, the Democratic party has no clear frontrunner. Less than 100 days before the first primaries in Iowa, the party candidates are offering fundamentally different policies and politics.

A recent edited volume, Why The Left Loses: The Decline of the Center-Left in Comparative Perspective, could provide Democrats with some insights on what (not) to do.

The center-left has borne the brunt of the political backlash against the Great Recession. Support for social democratic parties has been reduced to single digits in various west European countries (Greece, France, the Netherlands), while others are polling at record lows (Austria and Germany). Even in the UK, despite a short resurgence under Jeremy Corbyn, Labour is now polling at a postwar low of roughly 25%.

The Democratic party is faring much better than its foreign brothers and sisters, but this is in part because of peculiarities of the US political system – most notably the combination of a majoritarian electoral system and the crucial role of money. How can the Democratic party ensure that it does not suffer the same fate as social democratic parties in other western democracies?

All authors agree that the center-left’s move to the right – its adoption of neoliberalism – is the main source of the current crisis. While broadly associated with Tony Blair’s “Third Way” politics of the late 1990s, the origins go back to Bob Hawke’s Labour government in Australia of the early 1980s. Hawke was the first social democratic leader to argue that market delivery mechanisms could deliver egalitarian outcomes.

The neoliberal turn of the Democratic party took place between the Australian and British ones, with Bill Clinton’s shock victory in 1992 – ironically, Bill Clinton won with just 43%t of the vote, 5% less than his wife Hillary would lose the elections with 24 years later. Neoliberalism remained hegemonic within the party until Bernie Sanders’ surprisingly strong challenge in the 2016 primaries – partly riding the wave of the Occupy mobilization.

Why the Left Loses argues that social democratic parties were punished for their neoliberal turn by two diametrically opposed newcomers: the radical left and the radical right. The first process, known as “Pasokifation”, played out most brutally in Greece, where the center-left Pasok was demolished by the new left populist Syriza in 2012. Although the term was quickly applied to other countries, new radical left parties emerged in only a few countries and even in those (like Spain) Pasokification did not take place to the same extent.

Similarly, although it has become received wisdom in both media and political circles, social democratic parties did not lose primarily to the far right. More recent electoral research shows that they mostly lost to center-right parties in the first decade of the 21st century and to Green parties in the second decade.

Because of the specific US political context, the Democratic party does not face similar challenges from the left. The Green party is only a minor spoiler in US politics and the “radical left” is challenging the “liberal” establishment from within the Democratic party – ie Bernie Sanders and, to a somewhat lesser extent, Elizabeth Warren.

With the far right turn of the Republican party under President Trump, the Democratic party no longer has to worry about losing “centrists” to the Republicans. The challenge now comes exclusively from the far right. However, this challenge is quite limited in the US too. Media interest in Sanders-to-Trump voters overstates their actual electoral significance both then and now.

The editors conclude that center-left parties can only be successful if they change their ideological message away from neoliberalism and back to a more modern social democracy, but that this change must be combined with strong leadership and be in line with the political context. Of the three key candidates today, this would rule out Biden, who represents the old message, leadership and political context. It would be more favorable to Sanders, although he runs the same risk as Jeremy Corbyn in the UK: splitting the party establishment, and part of the base, thereby undermining the clarity of the party leadership and message.

Enter Elizabeth Warren, who is able to offer a new leftwing message without dividing the establishment and base. The Massachusetts senator is not just among the three most popular candidates, she is also the (clear) top second-choice candidate among the supporters of both Biden and Sanders. Moreover, with social democratic policies broadly popular among Americans, particularly among youth, but (the term) socialism still controversial, the country is ready for her program.

This leaves two key questions unanswered, in case Warren wins the nomination. First, is the Democratic leadership, and particularly Biden and Sanders, willing to follow their supporters and rally around Warren’s leadership? Second, is America ready for a female president? If the answers to these two questions are yes, the Democratic party might emerge as the shining star of social democratic politics next year.