Source: "Drawing the line"
From the article: "On March 28th they were to hear Benisek v Lamone, a case pitting Republican voters in Maryland against Democrats in the state’s House of Delegates. In 2011, the voters complain, legislators sabotaged the Republican Party in the sixth congressional district. A year after this “devastatingly effective” gerrymander, a House seat which a Republican, Roscoe Bartlett, had won for a tenth time in 2010 by 28 points went to John Delaney, a Democrat with presidential ambitions for 2020. Mr Delaney’s 21-point win in 2012 may show that Republicans were “singled…out for disfavored treatment”—“retaliation” barred by the First Amendment. The freedom of association, the plaintiffs contend, “guarantee[s] that no state may punish its citizens for their political beliefs”.
The Supreme Court heard Gill v Whitford last October (2017), and some seemed intrigued by is statistics-based approach pegged to the 14th Amendment’s equal-protection guarantee. But the conservative wing of the court was sceptical of the standard offered by those challenging a Republican gerrymander in Wisconsin. Chief Justice John Roberts derided it as “sociological gobbledygook”. For the statistics-shy, the First Amendment approach in Benisek may present an attractive alternative.