How Doug Jones Won

Comparing last night’s results for the Special Election in Alabama to prior elections in that state shows the path which brought Doug Jones his unlikely victory.  Like all special elections, the Alabama election unsurprisingly failed to mobilize as many voters as last year’s Presidential contest, but the turnout last night did exceed the 2014 mid-term figure by four percentage points.  Alabamians apparently thought this race was worth the effort.

Jones gained nearly as many votes in this special election as Hillary Clinton polled in November, 2016, despite an electorate 37 percent smaller than for the Presidential election.

Doug Jones expanded the Democratic electorate in the largest Alabama counties when we compare his results to those polled by 2014 Democratic gubernatorial candidate Parker Griffith.  (There was no Democratic candidate for Senator on the ballot that year.)

Jones won 671,151 votes last night, an improvement of 57 percent statewide over Griffith’s 427,787 total three years ago.  The graph shows clearly that Jones’s advantage grew as a function of county size as measured by total turnout.  His best performances were in Madison County, where aerospace center Huntsville is located; Shelby County, which includes suburban Birmingham; and Baldwin County, just east of Mobile.  Moore carried both of the latter counties over Jones but by severely diminished margins compared to Republican performance in prior elections. Jones doubled the Democratic vote in Lee County, home to Auburn University, and made a significant gain in Tuscaloosa where the University of Alabama is located.

Moore’s support, in contrast, was strongest in the smallest counties.  Here I am comparing Moore’s performance last night to the total vote cast in the Republican primary runoff election against Luther Strange late last September.  Moore needed to mobilize sufficient numbers of Strange voters to add to his own totals going into last night’s election.  He failed to do so.

Statewide Moore received about 35 percent more votes than he and Strange together polled in September.  However Moore saw his smallest gains in the largest counties, the opposite of the pattern we saw for Jones.

Running a simple regression of Jones’s lead over Moore against demographic variables shows the dominant power of mobilized African-Americans with smaller effects for the proportions of Hispanics and people with a college degree.

In a county with no blacks, no Hispanics, and no one with a college degree, Moore would beat Jones by 79 points, e.g., 89-10.  The size of the black population played the most important role in determining support for Jones.  His lead expanded by 1.6 percent for every one percent increase in the percentage of blacks.  Hispanics played a less significant role with a coefficient about half the size of that for blacks that barely achieves statistical significance.  The proportion of a county’s residents holding a college degree mattered nearly as much as the size of its black population. These three variables alone account for about ninety-four percent of the variance in Jones’s lead over Moore.

Jones’s victory with a margin of 1.5 percent over Moore suggests that the polls that included cell phone respondents were right on track.  As I wrote yesterday, “Taken together, [my analysis of polling data] suggests that Jones has averaged a 1-2 percent lead in polls taken since the Washington Post story that included calls to cell-phone users.”  Polls limited to landline households, which predicted a Moore victory, were off the mark.