… Using interviews conducted over Trump’s first six months in office — during which his approval slipped slightly nationally — Gallup determined the average approval in each of the 50 states.
It’s worth noting that in 47 of the states, Trump’s approval rating is now below the percentage of the vote he received. …
The more important factor here is that Gallup’s approval polling samples all adults, while voting results are, obviously, just those people who went to the polls. In other words, a lot of people dislike Trump who probably won’t go to the polls in 2020.
That said, though, there is a correlation between a president’s approval rating and his reelection prospects. Below, a comparison of Gallup’s November approval ratings with the results of a president’s reelection bid. CONT.
Philip Bump, Washington Post