people who identify as Republican may stop doing so if they disapprove of Trump, creating a false stability in his partisan approval numbers even as the absolute number of people approving him shrinks. Gallup data supports this idea, showing a four-percentage-point decline in G.O.P. identification since the 2016 election that is mirrored in other polling, though to a lesser extent.
https://www.nytimes.com/2017/07/19/...-of-support-may-be-smaller-than-it-seems.html
https://www.nytimes.com/2017/07/19/...-of-support-may-be-smaller-than-it-seems.html
