Cite as: 588 U. S. ____ (2019) 31 KAGAN, J., dissenting Ante, at 31; see League of Women Voters of Florida v. Detzner, 172 So. 3d 363 (2015). And indeed, the majority might have added, the Supreme Court of Pennsylvania last year did the same thing. See League of Women Voters, ___ Pa., at ___, 178 A. 3d, at 818. But what do those courts know that this Court does not? If they can develop and apply neutral and manageable standards to identify unconstitutional gerrymanders, why couldn’t we?6 We could have, and we should have. The gerrymanders here—and they are typical of many—violated the constitutional rights of many hundreds of thousands of American citizens. Those voters (Republicans in the one case, Democrats in the other) did not have an equal opportunity to participate in the political process. Their votes counted for far less than they should have because of their partisan affiliation. When faced with such constitutional wrongs, courts must intervene: “It is emphatically the province and duty of the judicial department to say what the law is.” Marbury v. Madison, 1 Cranch 137, 177 (1803). That is what the courts below did. Their decisions are worth a read. They (and others that have recently remedied similar violations) are detailed, thorough, painstaking. They —————— 6 Contrary to the majority’s suggestion, state courts do not typically have more specific “standards and guidance” to apply than federal courts have. Ante, at 31. The Pennsylvania Supreme Court based its gerrymandering decision on a constitutional clause providing only that “elections shall be free and equal” and no one shall “interfere to prevent the free exercise of the right of suffrage.” League of Women Voters, ___ Pa., at ___–___, 178 A. 3d, at 803–804 (quoting Pa. Const., Art. I, §5). And even the Florida “Free Districts Amendment,” which the majority touts, says nothing more than that no districting plan “shall be drawn with the intent to favor or disfavor a political party.” Fla. Const., Art. III, §20(a). If the majority wants the kind of guidance that will keep courts from intervening too far in the political sphere, see ante, at 15, that Amendment does not provide it: The standard is in fact a good deal less exacting than the one the District Courts below applied. In any event, only a few States have a constitutional provision like Florida’s, so the majority’s state-court solution does not go far.