There are 14 prominent Democrats who believe they ought to be next president of the United States. As many as a dozen more may join them. But not Eric Holder. Obama’s first attorney general announced on Monday that he had decided against a bid, saying he would instead focus on leading the National Democratic Redistricting Committee, a Democratic-aligned group that aims to curb GOP gerrymandering when the states redraw legislative maps after the 2020 census.

“I will do everything I can to ensure that the next Democratic president is not hobbled by a House of Representatives pulled to the extremes by members from gerrymandered districts,” he wrote in a Washington Post op-ed announcing his decision. This is familiar ground for Holder. He warned in this magazine last February that the Trump administration’s proposed citizenship question on the census “would have devastating consequences on the right to vote and to participate meaningfully in democracy,” and he often calls for the Electoral College’s abolition.

For the past 20 years, Republicans have exploited structural flaws in American democracy to amass disproportionate political power in Washington. The challenge for Democrats is how to reform that system to achieve their goals. While winning the presidency is an important step in that process, Holder’s decision shows how some of the presidential candidates could better advance a liberal policy agenda by staying out of the 2020 race.

The current crop of Democratic candidates seems to understand this, to varying degrees. Some have said they will support statehood for the District of Columbia and Puerto Rico, which would give representation in Congress to almost four million Americans and dilute the influence of conservative rural states. Massachusetts Senator Elizabeth Warren built her campaign around the theme of anti-corruption and proposed a wide-ranging legislative package to undermine special interests’ grip on Washington. Vermont Senator Bernie Sanders’s central theme is how extreme wealth inequality has warped the American democratic process. Without tackling these structural issues, major policy initiatives like the Green New Deal and Medicare for All don’t stand a chance of becoming law.

But not every Democratic contender seems to be taking a strategic approach to this problem. Beto O’Rourke’s near-upset of Texas Senator Ted Cruz in last year’s midterm elections shocked the state’s political scene and turned the former congressman from El Paso into a national figure. Top Democrats tried to persuade O’Rourke to challenge John Cornyn, Texas’s other incumbent Republican senator, for his seat in 2020. Even Senate Minority Leader Chuck Schumer reportedly pressed him to enter the race.