Last month, Republicans announced their plan for a comprehensive overhaul of the United States federal tax code, the first in decades. In characteristic fashion, President Trump promised, “I don’t benefit. I don’t benefit.” To clarify his point, he added, “I think very, very strongly, there’s very little benefit for people of wealth.” Lest those statements left any doubt, Trump later claimed, “I’m doing the right thing and it’s not good for me, believe me.” Notwithstanding the President’s promises, a New York Times analysis found that Trump could save over a billion dollars if his plan were to be passed into law. Seemingly responding to this reality, Trump later amended his sales pitch by claiming that “everybody benefits” from tax reform.

Tax reform fits squarely into the third category of conflicts tracked by this blog: government regulatory and policy decisions that benefit Trump and his family businesses. Americans deserve to know how the President would personally stand to gain if his proposal became law. Yet the extent of Trump’s conflict of interest remains unknown, and unknowable, because of his widely-criticized refusal to release his tax returns.

Unfortunately, California Governor Jerry Brown squandered an opportunity to force Trump to shed some light on his personal finances when he vetoed the Presidential Tax Transparency and Accountability Act, which had passed both houses of the state legislature with overwhelming support. The Act would have required all aspiring Presidential candidates to provide their tax returns to the California Secretary of State (who would then publish them online) before the candidate’s name could appear on the California primary election ballot. In his veto message, Governor Brown explained that while he “recognize[d] the political attractiveness—even the merits—of getting President Trump’s tax returns,” he worried about the “political perils of individual states seeking to regulate presidential elections in this manner.” Brown identified two specific concerns about the bill: its constitutionality and the potential “slippery slope” it might create.

Brown’s arguments ring hollow. They seem particularly unjustified in a time in which state action is one of the few viable bulwarks against Trump’s corruption. Fortunately, other states, including Massachusetts and New York, are considering similar proposals. Those states can do better than California. Here’s why they should:

• Transparency is vital. We expect our democratically elected politicians to represent the interests of their constituents—not govern like feudal lords seeking to enrich themselves. Richard Nixon began the modern trend of Presidents releasing tax returns when he did so while undergoing an IRS audit. That move allowed him to claim that he was being transparent (and famously, “not a crook”). While IRS rules require the President and Vice President’s tax returns to be audited every year, ensuring compliance with existing tax law doesn’t boost transparency or prevent corruption.
• The requirement is reasonable. Part of the cost of running for President is sacrificing a great deal of your privacy. But that’s understandable: when you ask millions of people to vote for you, they naturally expect to have more information about who you are. In vetoing the California bill, Governor Brown warned of a slippery slope—that tax returns might lead to “years of health records” or “high school report cards” or a “certified birth certificate” being required. I don’t find that to be a convincing excuse to simply do nothing while Trump rearranges the federal tax code to pass along more of his wealth to his children. For one thing, Brown’s examples bear little resemblance to tax records, which serve the important purpose of revealing potential conflicts of interest and have been disclosed by custom for decades. For another, an engaged media, the political process, and the courts all stand in the way of states attempting to implement any of his examples, which are significantly less policy-related and more intrusive and personal than tax returns.
• It just might work. It doesn’t matter that only “blue states” are likely to consider this legislation. Trump won the California, Massachusetts, and New York primaries; together, they gave him nearly a quarter of the delegates he needed to win the nomination. If just a handful of influential states institute tax return requirements, Trump will be faced with a real dilemma: embrace transparency or allow another Republican candidate to scoop up a significant number of delegates.
• The constitutional challenges are winnable and worth fighting. In his veto message, Governor Brown expressed concerns about the constitutionality of a state law requiring that presidential candidates disclose their tax returns before they can appear on the ballot. And yes, such a law is likely (perhaps certain) to draw lawsuits from the Trump campaign. But prominent constitutional scholars, including Erwin Chemerinsky and Larry Tribe, have argued that the law is constitutional. And even if, in the worst-case scenario, a ballot access law were to be struck down as unconstitutional, that would just put us back in the same place as we started, while in the process drawing even more attention to the opacity and potential corruption of the Trump administration.

I’d venture to say that the President’s tax plan is the most significant conflict of interest we’ve tracked here since his election. With it, he has the real opportunity to use his power to reap billions of dollars for himself and his heirs, while the public is none the wiser. But states’ independent constitutional authority to regulate elections provides an effective means to promote greater transparency about this likely conflict—which, one hopes, might stimulate greater accountability.