A banner showing Maryland’s 3rd Congressional District to illustrate how disjointed it has become. (Kate Patterson/For The Washington Post)

“IF WE want a better politics, it’s not enough just to change a congressman or change a senator or even change a president,” President Obama said in Tuesday’s State of the Union address. Instead of electing a few well-meaning people, the president insisted, “we have to change the system to reflect our better selves,” altering “not just who gets elected, but how they get elected.” Mr. Obama speaks from experience: He promised to be a political change agent in the Oval Office, and, seven years later, the country’s politics are more fractured than when he started.

The truth is, as the president also acknowledged Tuesday, “our brand of democracy is hard,” with a certain amount of gridlock built into its system of checks and balances. No magic solution can bridge ideological and cultural rifts. But there are reforms that could help.

One such would be ending “the practice of drawing our congressional districts so that politicians can pick their voters and not the other way around,” as Mr. Obama said. Gerrymandering, in which state lawmakers draw legislative district boundaries to maximize partisan or incumbent advantage, warps Americans’ representation in Washington and in statehouses across the country. Among the most egregious examples are the embarrassingly partisan congressional district maps that Democrats drew in Maryland and Republicans drafted in North Carolina.

The strategy involves packing people who tend to vote for the opposite party into a few districts and spreading out the rest of the opposition among the others. The use of this technique contributes to results such as these: In 2012, a year in which Mr. Obama carried Pennsylvania by five points, 13 of the state’s 18 congressional districts went to Republicans. In a given election, a majority of Americans might vote for Democrats for Congress, but Republicans could still hold the majority of seats. Needless to say, this tends to make Congress less responsive to the will of the majority.

Mr. Obama offered one idea to even things out: Let a bipartisan or nonpartisan committee draw the maps. Voters in Arizona and in California took map-drawing responsibilities out of partisan lawmakers’ hands, resulting in maps that preserved majority-minority districts required under the Voting Rights Act and also created a few more competitive seats. The Supreme Court ruled last term that this is constitutionally acceptable.

Redistricting commissions can’t eliminate distortions that result from population patterns. Democrats tend to cluster tightly in cities, making it more likely that their votes will be packed into a few urban districts. But the distortions do not have to be as big as they are now.

Even if redistricting reform had only a modest effect on election results, reform would increase the legitimacy of the system. Unfortunately, the same partisan politicians who benefit from existing rules cannot be counted on to impose such reform on themselves. Voters, state by state, may have to demand it, either by electing legislators who support redistricting commissions or by approving ballot measures that give lawmakers no choice.