This represents a pretty dramatic rise, but Buttigieg isn’t alone in his polling surge. Harris and Sen. Bernie Sanders also had notable increases in their survey numbers around the time of their campaign announcements. And now it appears that Biden is enjoying his own polling bump following his entrance into the race. Nonetheless, those candidates weren’t polling at 0 percent like Buttigieg was. But now the Indiana mayor finds himself getting around the same amount of support as former Rep. Beto O’Rourke, a development that few people would have bet on just a couple of months ago. Buttigieg’s numbers have dipped slightly in the past couple of weeks, but that could be a side effect of Biden entering the race — Sanders and other candidates have also experienced a slide in their numbers since Biden announced he was running on April 25.

As Vox noted last month, Buttigieg has made himself incredibly accessible to the media, which in turn has helped grow his profile, especially in the wake of the CNN town hall. But now Biden is capturing a ton of media attention, to the detriment of his Democratic opponents. And as we know from past elections, media coverage is an influential part of the “invisible primary” — the period before voting begins, when donors, the media and party operatives are the biggest influencers of who leads the presidential nomination contest. Free airtime for a candidate can be the equivalent of millions of dollars in advertising, and it has helped Buttigieg attract support and donors.