WASHINGTON, DC – America’s presidential election is still nearly two years away, and few candidates have formally thrown their hats into the ring. But both Democrats and Republicans are hard at work figuring out what will appeal to voters in their parties’ respective primary elections – and thinking about what will play well to the electorate as a whole in November 2016.

The contrast between the parties at this stage is striking. Potential Republican presidential candidates are arguing among themselves about almost everything, from economics to social issues; it is hard to say which i.deas and arguments will end up on top. The Democrats, by contrast, are in agreement on most issues, with one major exception: financial reform and the power of very large banks.

The Democrats’ internal disagreement on this issue is apparent when one compares three major proposals to address income inequality that the party and its allies have presented in recent weeks. There are only small differences between President Barack Obama’s proposals (in his budget and State of the Union address), those made in a high-profile report from the Center for American Progress, and ideas advanced by Chris Van Hollen, an influential member of Congress. (For example, Van Hollen recommends more redistribution from higher-income people to offset a larger tax cut for middle-income groups.)

Against this backdrop of programmatic unity, the difference of opinion among leading Democrats concerning Wall Street – both the specifics of the 2010 Dodd-Frank financial reforms and more broadly – stands out in bold relief.

On Dodd-Frank, Democrats – including Obama – are apparently of two minds on the extent to which they should stick up for their own reforms. In December, the White House agreed to a Republican proposal to repeal a provision of Dodd-Frank that would have limited the risk-taking of the country’s largest banks (in fact, the proposal’s language was drafted by Citigroup).

More recently, however, Obama has threatened to veto any further attempts to roll back financial reform. And now he is proposing to impose a small tax on the largest banks’ liabilities, which he hopes will encourage "them to make decisions more consistent with the economy-wide effects of their actions, which would in turn help reduce the probability of major defaults that can have widespread economic costs.”

In contrast, the Center for American Progress report devoted very little space to financial-sector reform – in the authors’ view, such issues hardly seem to be a high priority. Van Hollen does have some concerns – and proposes a financial transaction tax to reduce speculative activities.

But a serious challenge to all of these views has now emerged, in proposals by Senator Elizabeth Warren, a rising Democratic star who has become increasingly prominent at the national level. In her view, the authorities need to confront head-on the outsize influence and dangerous structure of America’s largest banks.

Warren’s opponents like to suggest that her ideas are somehow outside the mainstream; in fact, she draws support from across the political spectrum. In last month’s fight against Citigroup’s successful effort to roll back Dodd-Frank, for example, Warren’s allies included the House Democratic leadership, the Independent Community Bankers of America, Republican Senator David Vitter, and Thomas Hoenig (a Republican-appointed vice chair of the Federal Deposit Insurance Corporation).

Warren’s message is simple: remove the implicit government subsidies that support the too-big-to-fail banks. That single move would go a long way toward reducing, if not eliminating, crony capitalism and strengthening market competition in the financial sector. This is a message that plays well across the political spectrum. And growing support for Warren’s ideas helps the Federal Reserve and other responsible regulators in their efforts to prevent big banks from taking on dangerous levels of risk.

The big Wall Street banks have enormous influence in Washington, DC, in large part because of their campaign contributions. They also support – directly and indirectly – a vast influence industry, comprising people who pose as independent or moderate commentators, edit the financial press, or produce bespoke "research” at think tanks.

These megabanks are making a determined attempt to repeal as much of Dodd-Frank as possible, and the House Republicans seem keen to help them. This is not an issue that will fade away.

The Democrats need to figure out their policy on Wall Street. In the past, they have simply gone for the campaign contributions, doling out access and influence in exchange. It is now obvious that this is not consistent with defending what remains of Dodd-Frank.

Warren offers a plausible, moderate alternative approach to financial-sector policy that would play well in the primaries and attract a great deal of support in the general election. Will the Democrats seize the opportunity?

Simon Johnson, a former chief economist of the IMF, is a professor at MIT Sloan.

Copyright: Project Syndicate.