Michael Herron has written this article forthcoming in the Election Law Journal. Here is the abstract:

The aftermath of the 2018 midterm election in North Carolina was marred by allegations of absentee ballot fraud in the state’s 9th Congressional District, most notably in Bladen County, one of eight counties in North Carolina that intersects this district. We show with a difference-in-difference design that Bladen County’s election returns in 2018 are indeed highly anomalous: compared to congressional candidates in other North Carolina counties, the 9th District’s Republican candidate for the United States House of Representatives had in Bladen County a mail-in absentee vote share inconsistent with his level of Election Day support. Bladen County’s 2018 congressional election results are also anomalous when compared with North Carolina congressional elections of 2010, 2012, 2014, and 2016, and they are likewise anomalous when compared with recent congressional elections in Arkansas, Georgia, and Oklahoma, three states that tabulate election results in a way that facilitates comparisons with North Carolina. Beyond the 2018 midterm, congressional election returns in Bladen County exhibited anomalous mail-in absentee voting patterns in the 2018 Republican primary and in the 2016 general election. Finally, rates of requested and returned mail-in absentee ballots in the period surrounding the 2018 midterm were anomalous in both Bladen and neighboring Robeson counties. Our statistical results are consistent with investigative findings presented in February 2019 to the North Carolina State Board of Elections, which voted unanimously on February 21, 2019, to hold a new election in Congressional District 9.