The methodology says “We used iSay/Ipsos, Dynata, Disqo, and other leading panels to recruit the nationally representative sample”. (They also say elsewhere that “Responses were census-balanced based on the American Community Survey 2021 estimates for age, gender, region, race/ethnicity, education, and income using the “raking” algorithm of the R “survey” package”.)
The methodology says “We used iSay/Ipsos, Dynata, Disqo, and other leading panels to recruit the nationally representative sample”. (They also say elsewhere that “Responses were census-balanced based on the American Community Survey 2021 estimates for age, gender, region, race/ethnicity, education, and income using the “raking” algorithm of the R “survey” package”.)