|Dialect map ᔥ The Crux|
Labov suggests that it’s these deep-seated political disagreements that create an invisible borderline barring the encroachment of Northern Cities Vowels. When he looked at the relationship between voting patterns by county over the last three Presidential elections and the degree to which speakers in these counties shifted their vowels, he found a tight correlation between the two. And the states that have participated in the vowel shift have also tended to resist implementing the death penalty.
Do vowel-shifters sound more liberal to modern ears? Yes, at least to some extent. Labov had students in Bloomington, Indiana, listen to a vowel-shifting speaker from Detroit and a non-vowel-shifter from Indianapolis. The students rated both speakers as equal in probable intelligence, education and trustworthiness. They also didn’t think they would have different attitudes about abortion (both speakers were female). But they did think the vowel-shifting speaker was more likely to be in favor of gun control and affirmative action.ᔥ The Morning News