How the Social Democrats came to lead the German polls, up-close

Hi, this is Lisa, responsible for the blog at Datawrapper. You might remember me from last week, where I zoomed out and showed polling results for German parties from the last thirty years. For this Weekly Chart, I do the opposite: I zoom in and show the results from the last thirty days.

German election polls have been crazy lately. For months, the most interesting question when looking at the polls had been: "Will the Greens be able to toss the Christian Democratic Union (CDU) from first place before the federal election on September 26?" But in the last 20 days, not the Greens rose to first place, but — plot twist — the Social Democratic Party (SPD) and its chancellor candidate Olaf Scholz.

Charts that show polls up close are rare. That's because such charts would be fairly boring most of the time: voters just don't change their opinions so quickly — usually. Here are the polling numbers for the last 1.5 years: You can see that over many months, nothing much changes:

But in the past days, the numbers did change dramatically. And yet: The rise of the SPD (and how special that is) is far easier to see in the 1.5-years view than in the 30-days view at the top of this article.

The 1.5-years view shows us what most voters (and chancellor candidates) want to know: Who's leading the polls? Where is the trend going? The average of these individual polls lets us see the forest instead of the trees. But it also gives us a (too) simple feeling of, "Nothing can stop the SPD now; it'll continue to rise!" (Hans Rosling called that the "Straight Line instinct.")

The 30-days view provides a more complicated perspective. It shows margins between the CDU/CSU and the SPD of as little as two and as much as six percentage points. It shows the uncertainty, the volatility of polls far better. But it's also harder to see the pattern at all. We don't see a stark increase here, but a slight upwards trend for the SPD.

Different time spans can give readers different insights — these two charts are one more example of that phenomenon.

That's it for this week! For more (live-updating!) visualizations about the German election, visit our article "How to visualize polls and results of the German election with Datawrapper." We'll see you next week!