One of the 50 predictions made by Fortune magazine in November 2017 runs as follows: "The court’s key swing vote, Anthony Kennedy, has a flair for the dramatic. He will cast the deciding vote in a 5–4 ruling in Gill v. Whitford that will declare the serpentine redrawing of election districts for political purposes to be unconstitutional."
Gill v. Whitford is concerned with Wisconsin's 2011 redistricting, which in the 2012 elections gave the Republicans 60% of the seats from 49% of the votes. A District Court decision ruled that the redistricting was in violation of the Fourteenth Amendment to the US Constitution on the grounds that it deprived everyone but Republicans of "equal protection". The case was appealed to the Supreme Court, which is expected to decide it in mid-2018. The plaintiffs' case is based in part on various measures of gerrymandering, such as the so-called efficiency gap, and if the District Court's decision stands then it will likely make it easier for future gerrymandering cases to be brought on the basis of such measures.
The question resolves negative if, by the end of 2018, the Supreme Court upholds the appeal by Gill et al, and positive if, by the end of 2018, the repeal is rejected. In other cases, it resolves ambiguous.
Note on resolution conditions and title: In principle the Supreme Court could reject the appeal but deliberately not endorse any particular way of measuring gerrymandering, or could endorse some clear way of measuring gerrymandering that somehow doesn't reckon the Wisconsin redistricting to be a case of gerrymandering. I don't think these are likely enough outcomes for the slight divergence between title and resolution conditions to be a problem, but I'm willing to be persuaded.
(edited 12/21/17 plaintiffs -> defendants for consistency with rest of question.)
(edited 1/10/17 for further clarifying wording.)