Over the last year, I’ve gotten really interested in differential partisan nonresponse bias and considering the idea of weighting by party identification. I wanted to check for partisan nonresponse bias effects in Trump approval rating polls (similar to the way done in this post on your blog ), and I came up with the below graphs about a week ago. I explain details here , but interestingly there appears to be a strong relationship (R= .45) between the unweighted partisan distribution of a poll and Trump evaluation if you only look at approval rating polls that don’t weight by party or past vote. It feels like a crude way of measuring partisan nonresponse, but it’s still interesting that 1) a fairly strong relationship already exists and 2) it’s occurring outside of just a campaign season context . For the latter point, I’ve been contemplating whether this suggests partisan nonresponse is a systemic issue that polls of any kind must always deal with.