The United States of America has long been considered the homeland of capitalism and New York its capital. But as of lately, Democratic Socialists are winning a number of elections.

In Latin America, an entire series of countries is turning away from left-wing leaders and is electing presidents from the right. In Europe, parties that are in a Socialist tradition have long tried to modernize or even distance themselves from the Socialist brand.

Not so in the United States of America. With Zohran Mamdani, a Democratic Socialist won the mayoralty of New York. And just this week, three other Democratic Socialists won primary elections with some of them beating long-term incumbents. And even in other parts of the country, Democratic Socialist challengers beat incumbents in primaries.

I see a series of reasons for their wave of success (in no particular order):

• Bernie Sanders and the progressive moment have used the shock of Donald Trump’s election to the White House to get progressives involved in the political process. If people are angry or anxious, they want to do something. Sanders and his allies gave them something to do, for example to run for school board. In other words, the success of this week is not falling from heaven, progressives are reaping the benefits of groundwork that was done a while ago.
• As I write in my book “Beat the Incumbent,” elections with an incumbent are foremost a referendum on the incumbent. In this case, it’s a referendum on the Democratic leadership in Washington DC. It’s a classic situation where the Democratic base is angry with its leadership in Washington DC (similar to how Republicans were angry with their leadership in 2010 and 2014). The Democratic base wants somebody that stands up much more assertively to Donald Trump.
• Democratic incumbents waste a gazillion USD on TV advertising. A lot of these ads are done poorly as they really look and feel the same, that is, like political propaganda. And as we have seen in military campaigns just recently, the air war is not enough. One needs ground troops to win. In politics, a challenger campaign has the advantage that it can have a unique sort of energy to it. Nobody goes door to door in their spare time for the summary of the compromise. In fact, compromise is something one can live with, but it takes radical ideas to create activism.
• Challengers need a specific issue to crystallize their call for change. In several Democratic primaries, the war in Gaza is an issue that works for the challengers and is a liability for the incumbents.
• In several cases, younger challengers are beating noticeably older incumbents. I have worked for candidates in their twenties and for others in their eighties and it’s rarely about age per se. It’s about the duration in office.
• Lastly, capitalism right now doesn’t deliver particularly well for many average Americans. The U.S. economy is doing reasonably well on paper, but the vast majority of Americans either don’t feel it or don’t benefit from it. In other words, maybe Socialism has not become that much more appealing, but defending the status quo has become much more difficult.