Romney received 59% of the white vote nationally in 2012 according to CNN Politics exit polling figures (which do not exist for 19 states), but underperformed that with whites in 21 states, losing the white vote outright in 8 of them:
California 53%
Colorado 54%
Connecticut 48%
Illinois 52%
Iowa 47%
Maine 40%
Maryland 55%
Massachusetts 42%
Michigan 55%
Minnesota 49%
Nevada 56%
New Hampshire 47%
New Jersey 56%
New Mexico 56%
New York 49%
Ohio 57%
Oregon 44%
Pennsylvania 57%
Vermont 33%
Washington 46%
Wisconsin 51%.
On an average percentage basis, Romney garnered just under 50% of the white vote in these states, losing them all to Obama, underperforming his own national showing among whites by 18% on average.
The white vote is especially interesting in the four states in the east which Romney lost by just 429,522 votes in the aggregate (2.3% of the total votes cast), which together with his 206 electoral college votes would have given him the 270 necessary to win the election:
Florida, lost by 74,309 votes (0.87% of the total vote cast there in 2012)
Virginia, lost by 149,298 (3.87%)
New Hampshire, lost by 39,643 (5.57%)
Ohio, lost by 166,272 (2.97%).
In Florida Romney outperformed himself with whites, getting 61% of the white vote (67%), but needed 62.4% of it to win. In Florida Romney needed to do 2.3% better with whites to win than he did.
In Virginia Romney also outperformed himself with whites, getting 61% of the white vote (70%), but needed 66.53% of whites to win. That meant doing 9.1% better with whites in Virginia than he did.
In New Hampshire Romney severely underperformed himself with whites, getting just 47% of the white vote (93%). He needed to increase that to 53% to win it. In other words, Romney needed to do 13% better with whites in New Hampshire than he did.
And in Ohio Romney also underperformed himself with whites, getting 57% of the white vote in 2012 (79%). To win it he needed 60.8%. In other words, Romney needed to do 6.7% better among whites in Ohio to win than he did.
So on average Romney needed to do about 8% better with whites than he did in order to win these four states and with them the election. But overall it was Romney's severe underperformance with whites from California to Vermont which meant that even that was highly unlikely to happen in the end.
