Apart from Maine, New Hampshire and Vermont - all Eastern seaboard states - only states boasting an overwhelming majority of white voters (ranging from 93.5% to 84.5% of the total population) were considered (since to include states with higher percentages of African-Americans and other minorities would only skew the picture due to their sizable pro-Obama vote).
Table 1
State
White Population
Annual Household Income
Education BA degree or higher
McCain vs. Obama vote differential
West Virginia
93.5%
$37,989
19.9%
13.12%
Idaho
93.0%
$47,576
26.8%
25.43%
Wyoming
92.6%
$53,207
26.7%
32.24%
Utah
90.7%
$56,633
32.5%
28.1%
Nebraska
88.3%
$49,693
30.6%
14.93%
Kentucky
87.6%
$41,538
23.2%
16.23%
Colorado
87.1%
$56,993
39.4%
- 8.95%
Wisconsin
87.1%
$52,094
29.0%
- 13.91%
N. Dakota
87.0%
$46,032
28.9%
8.63%
Kansas
86.4%
$50,177
32.3%
14.96%
S. Dakota
84.4%
$46,032
27.8%
14.48%
The reader is invited to compare these results with those which obtained in the course of the 2012 election cycle.
Interpretation of Results
If we opt for annual household income, coupled with education, as the most reliable indicator of one's status as a member of the working class, then West Virginia wins the contest hands down as the state in which white working-class voters comprised the greatest chunk of its overall (white) population, with Kentucky, Idaho and both Dakotas close runners-up.
The Curious Case of West Virginia
There still remains to explain the rather poor (only 13.12%) pro-McCain showing in West Virginia, especially in light of the state's having scored the highest in terms of both the percentage of its white population in general and its working-class voters (as defined above) in particular: By all reasonable accounts, it should have been near the top of the list.
Not only did Trump carry the state with a staggering "68.5% of the vote.the largest share of the vote in any state" and an unprecedented 42.2% victory margin, making it only second in that category to Wyoming; duplicating what he'd done in Oklahoma, he had also won West Virginia's every county.