In most political disputes, there will usually be an argument that helps the left and an argument that helps the right. A common rhetorical tactic is to insist that one side or other is in fact being neutral, while the other side is being partisan. In the abstract, these arguments should not work because neither side is being neutral. But in various areas of the law, there are liberal institutional asymmetries--legal principles that ensure the liberal position is seen as the neutral baseline.
One of the largest asymmetries was (past tense) the Voting Rights Act. I wrote in October:
Because African American and Hispanic voters tend to vote for Democratic politicians, Democrats will benefit from VRA claims. By contrast, because White voters tend to vote for Republican politicians, Republicans will less likely benefit from VRA claims. What is the upshot? Gerrymandered maps in the South drawn by Republican legislatures are routinely blocked under the VRA, while gerrymandered maps in the North drawn by Democratic legislatures are far more likely to survive.