America's Unwritten Constitution: The Precedents and Principles We Live By by Akhil Reed Amar

cleverly drawn so as to be a microcosm of the state as a whole.
    Despite these problems, the Court was wise to stop where it did. Each of the four most salient subspecies of gerrymandering—racial gerrymandering, bipartisan gerrymandering, one-party gerrymandering, and incumbent-protective gerrymandering—implicated a unique cluster of constitutional considerations, and none of these clusters supported unilateral judicial intervention.
    First, when governments have tried to fashion insidious district lines to disadvantage racial minorities, the modern Court has not faced a pressing need to develop its own implementational sub-rules based directly on the Fifteenth Amendment. Congress has already done much of the heavy lifting, via the 1965 Voting Rights Act and a series of subsequent statutory amendments. Enacted pursuant to Congress’s explicit enforcement authority under the Reconstruction Amendments, this landmark law has created an assortment of effective statutory tools—some to be wielded by courts, others by the Justice Department—to combat laws and practices that improperly dilute the voting power of racial minorities. This subspecies of gerrymandering highlights an important lesson: Federal courts arenot the only branch of government tasked with faithful implementation of the Constitution; nor are courts always the branch best suited to address every constitutional issue.
    Consider next the category of bipartisan gerrymanders. In jurisdictions where the two major parties, Republicans and Democrats, have worked together to draw district lines that favor these two parties and freeze out all third parties, these bipartisan “collusions” have generally not violated the Constitution. Rightly read, the Constitution in fact sanctions a self-perpetuating and self-stabilizing two-party system. No elaborate Court doctrine is called for here, because the practice is constitutionally proper. 14
    For different reasons, partisan gerrymandering designed to advantage one of the two major parties at the other party’s expense also calls for judicial restraint. To begin with, any judicial intervention would be messy in the extreme. Few, if any, easy, workable, and principled sub-rules present themselves as plausible scripts for a large judicial role to neutralize partisanship in the drawing of district lines.
    By contrast, in pure right-to-vote cases, such as Harper and Kramer , the basic framework was easy enough to construct: All adult-citizen, non-felon residents are presumptively eligible voters. This is the group textually identified by section 2 of the Fourteenth Amendment, as updated by the later Woman and Youth Suffrage Amendments. * It is also the lived-constitutional baseline suggested by actual modern practice in the fifty states. Some small questions have arisen at the margins—for example, how long a residency period may a state require?—but even here, actual practice and common sense have narrowed the range of plausible answers. Similarly, we have seen that the Reynolds rule offered a workable way to deal with malapportionment (although here, too, smallish questions at the margin needed to be addressed). 15
    But no comparably clean sub-rule exists to regulate district shape. In a sense, all districting is gerrymandering. No district map is neutral. How can principled judges treat like cases alike when each district map seems utterly unique and not easily comparable to any other map in any otherstate or census cycle? Perhaps the only clean approach would be to require each state to adopt some form of statewide proportional representation, but this audacious mandate would oblige every state to move beyond a single-member district system with deep historical roots almost everywhere in America.
    The lesson here is that on some issues a court’s implementational sub-rules may slightly underprotect certain constitutional values, just as on other issues the rules slightly overprotect. In both situations, there