Viewers got a substantive back-and-forth among the top Democratic presidential candidates on Sunday night, one that could provide a good foundation for determining support as the election draws near.

Sen. Bernie Sanders came across as the ideological firebrand of the race, given to sweeping statements and epic proposals that promise far more than a President Sanders could ever deliver. And in the case of his pronouncements on the evils of Wall Street and corporate America, that's a good thing. Income inequality has certainly grown and must be addressed. But the world is not so dark as Sanders paints it. In his zeal to right wrongs, his proposals — should they ever come to pass — likely would bankrupt the American economy and put businesses at too severe a disadvantage in a global marketplace.

Hillary Clinton left no doubt that she is the incrementalist. Where Sanders talks of a massive single-payer plan that would leave no health want unsatisfied, Clinton aims lower: tweaking the Affordable Care Act, tackling the high cost of prescription drugs, looking for manageable ways to curb costs. These goals are not visionary, but they have the virtue of being far more attainable. It's also refreshing whenever a Democrat acknowledges that rising costs in any area aren't sustainable.

Sunday's debate also saw the first significant embrace of President Obama's agenda by Clinton. That was a smart move. Obama's job approval ratings among Democrats average 80 percent, and Clinton would be wise to tap into the loyalty the president still generates among the faithful. Distancing herself from Obama would not be enough to endear Clinton to Republicans and, in such a polarized atmosphere, would cost her some Democrats, particularly in minority communities.

In a primary that's following a more typical trajectory than that of the Republican contest, a bit of Sanders' progressive populism is rubbing off on Clinton. She beat the democratic socialist to the punch in Sunday's debate when she raised the lead-tainted water crisis in Flint, Mich., where thousands of children may face permanent brain damage from a misguided attempt to cut costs.

"If the kids in a rich suburb of Detroit had been drinking contaminated water and being bathed in it, there would have been action," Clinton said. Sanders had earlier called for the resignation of Michigan Gov. Rick Snyder.

Similarly, Sanders, after repeated attacks by Clinton on his gun control position, modified his stance to include greater support for some measures.

No one candidate, on either side, will have all of the answers. Evolution on positions is to be expected and even demanded. Ideological warriors may have some appeal early on, but it's hard to govern from the edge.