See for instance this item on 'democratic commitment'. The item asked experts to place the party on ranging from "priortizing own political gain" (0) to "priortizing democratic rules and norms" (10).

That produces this picture : (only radical left and radical right shown). 5/

Here is a plot of the variables Overall Left-Right Position and Populism. You can play with the data yourself using our Shiny App!

Find it on our website: poppa-data.eu 3/