First of all, I haven't read that yet and don't know what policies or decisions they're basing that on, but Democrats love to talk big and then not actually do anything, so if it's just based on campaign promises and not actual voting history, then it's garbage data. But also, if you look at the numbers, even that site shows Democrats staying basically the exact same. It technically shows a negligible shift to the left, but it's basically 0. It's also +4 years old, which was a big difference in the political climate, and was before Kamala started courting republicans with her messaging. It was before the entire 2024 election season, and most democrats have moved way further right since Trump got elected again. It also states that Republicans have moved way to the right, while Democrats have stayed the same. So I'm not sure what you're basing your info on, but just a quick look at the Senate voting history shows Democrats are basically right-wing now. They've pretty much abandoned all pretense of even being centrist.