Sen. Bernie Sanders and Hillary Clinton participate in the PBS NewsHour Democratic presidential candidate debate. (Photo by Win McNamee/Getty Images)

During Thursday night's Democratic presidential debate in Milwaukee, the two candidates discussed health care.

Bernie Sanders argued for an expansion of Medicare to cover everyone in the country. "In my view, health care is a right of all people, not a privilege, and I will fight for that," he said.

Replied Hillary Clinton: "I can only say that we both share the goal of universal health-care coverage." But her solution to achieving that goal is different. "Why I am a staunch supporter of President Obama's principal accomplishment -- namely the Affordable Care Act," she said, "is because I know how hard it was to get that done."

"[W]hat President Obama succeeded in doing was to build on the health-care system we have, get us to 90 percent coverage," she said. "We have to get the other 10 percent of the way to 100. I far prefer that and the chances we have to be successful there than trying to start all over again, gridlocking our system, and trying to get from zero to 100 percent."

This exchange, in a very simple way, gets to the heart of the difference between the two candidates. Sanders dislikes how health care works and pledges to overhaul it. Clinton pledges to make it incrementally better, building on what has already been done. Sanders wants to replace the 90 percent with 100 percent. Clinton wants to add 10 percent.

To accomplish his plan, Sanders suggests that his election will be the start of a political tsunami -- a revolution of people standing up to challenge the status quo. We noted earlier this week that Sanders and Donald Trump have parallel philosophies on how to avoid the taint of political money: Sanders relies on huge influxes of donations and Trump has his own accounts from which to draw.

There's a similarity on political efficacy that mirrors how they look at money. Sanders pledges that those donors will be the political leverage he needs to effect change. They'll be/they are the revolution. Trump asserts that he'll make change through sheer force of will. There's no real evidence that either strategy will be particularly effective, and the tendency of each to lump in clearly unattainable ideas -- Trump's Mexico-paid wall, for example, or Sanders's pledge on prisons -- makes even more skepticism warranted.

Clinton tried to point that out repeatedly last night. "[W]e have a special obligation to make clear what we stand for," she said, "which is why I think we should not make promises we can't keep, because that will further, I think, alienate Americans from understanding and believing we can together make some real changes in people's lives." It's perhaps the best rejoinder she can offer, because "let's make an incremental improvement over time" is a much less compelling campaign argument than "toss the bums out, and let's start fresh" -- particularly this year.

But Clinton doesn't get a pass entirely. She, too, would face a Republican House and a Senate with a Republican majority -- or at least a caucus that would be big enough to filibuster legislation. How's she going to make change?

"I think once I'm in the White House we will have enough political capital to be able to do that," she said during the debate -- betraying through her body language that this would probably not happen. The election of Hillary Clinton will not bring Republicans to the bargaining table, chastened, any more than the election of Barack Obama -- the closest thing to a Sanders-style revolution that we've seen in recent years -- got Republicans to play ball.

The most likely scenario for an incoming Democratic president is the scenario we see now: Stalemate. As an illustration of the differences between the candidates, though, this disagreement over health care reveals a lot.