The other day, I noted that it might be time to start hoping for a real Democratic presidential primary. Not solely because Hillary Clinton’s handling of the email mess shows she might benefit from being challenged, but also because there are real differences among Democrats that would benefit from an airing.

Former Maryland governor Martin O’Malley, who has been talking about challenging Hillary Clinton from the left, has given an interview to Salon’s Joan Walsh that provides a preliminary glimpse into what such an intra-Dem debate might look like.

O’Malley seems to throw his lot in with what is widely being called the “Elizabeth Warren wing of the Democratic Party.” The divide on economic policy between the Warren-ites and the more moderate Democrats tends to be exaggerated — there’s probably more consensus on these matters among Democrats than there has been in many years — but there are real differences, and they matter.

For instance, O’Malley comes out for expanding Social Security (Obama has flirted with cutting it), arguing: “Right now we’re facing a looming retirement crisis in our country. People who used to have personal savings, or pensions, don’t have them.  More and more people are going to be relying solely on Social Security.” Some high profile Democrats, such as Warren, have endorsed this idea, which would be funded by lifting the cap so higher earners pay more into the system, while re-indexing for inflation to boost benefits. This goal is shared by some Dem constituencies, such as organized labor and activist groups. To my knowledge Clinton has not said whether she favors this.

O’Malley also declares his support for reinstating Glass-Steagall, i.e., separations between commercial and investment banks. This goal has also been championed by Warren, on the grounds that it could minimize the risks to the financial system posed by Wall Street “high stakes gambling.” O’Malley mocks fellow Democrats for “supporting Dodd Frank lite,” suggesting that they are mostly doing so because “we have monied interests tying Congress in knots,” an apparent effort to speak to Democratic voters who believe their party is too beholden to Wall Street.

The original Glass-Steagall, of course, was repealed under a president also named Clinton, which is one of the reasons many claim Hillary Clinton is “too cozy with Wall Street.” I’m a bit skeptical of that claim, but there are plainly differences among core Democratic constituencies over how far to go in regulating Wall Street, and a debate on this topic would be helpful and clarifying for Democratic voters.

O’Malley also brings up a topic we rarely hear about these days: Raising the income threshold for workers to qualify for overtime pay. The Obama administration will soon announce a rules change raising the threshold, and some liberal economists expect him to set it lower than he might. This is not a small matter: Going big on overtime pay might be the single most dramatic thing a Democratic president might do unilaterally to help the middle class — and if a Dem is elected in 2016, he or she will face a GOP House. O’Malley also talks about the need to boost the collective bargaining power of workers, which would be key to any serious effort to combat inequality. Clinton, too, is reportedly thinking along these lines, but still, debate on these topics would be great for the Democratic audience.

Then there’s the possible nuclear deal with Iran, a topic on which Clinton has been vague, and the argument over the proper parameters of the conflict with ISIS, a topic on which Obama and many Democrats disagree.

Yes, there is a lot of consensus among Democrats on the broad economic strokes: Higher taxes on capital gains and inherited wealth to fund middle class tax relief. More investments in infrastructure and education, particularly subsidized community college. Universal child care and early education; national family leave and sick leave policies designed to enhance workplace flexibility. A minimum wage hike. But there are remaining disagreements among core Dem constituencies and among party actors.

Can anyone force a real primary? Should anyone try? There has been a lot of snickering about how O’Malley can’t possibly mount a serious challenge to Clinton, and for all I know, that may be right. But as Jonathan Bernstein has explained, even if Clinton’s nomination appears close to inevitable, there really are a number of serious Democrats out there, and even the effort to compel a contested primary might help the party:

It’s good for the party to have competition, because it gives party actors leverage over the candidates, and therefore helps force the nominee, if elected, to be loyal to the party as president.

In other words, the debate itself is a worthy goal, even if it might have little chance of changing the outcome.