At the Jan. 17 Democratic debate in Charleston, S.C., Democratic front-runner Hillary Clinton went out of her way to stress her ties to President Obama. (Peter Stevenson/The Washington Post)

At times during Sunday’s Democratic debate in Charleston, S.C., Hillary Clinton’s pitch to voters seemed simple: Elect me and get four more years of President Obama’s policies.

At the same time, she sought to cast Bernie Sanders as anti-Obama, focused on trying to undo the president’s signature health-care law and opposing Obama in other ways.

In a sense, it was “revolution” versus “continuation.”

“Meet the Press” host Chuck Todd took note of that particular construct during a commercial break in the middle of the debate.

"One thing of note here: Bernie Sanders very much being the sort of revolutionary candidate, major change, and you've heard a lot of Hillary Clinton saying things like she wants to build on the things that President Obama did, wrapping herself in President Obama," Todd said.

That's right. Sanders regularly uses the word “revolution." On Sunday he called for a revolution in the American health care system, and Clinton pounced on that moment, accusing Sanders of wanting to “tear up” the Affordable Care Act and “start over again.” The subtle implication is that Sanders wants to undo what Obama has accomplished in office, and opposes him on a personal level.

Then, when pushed on her Wall Street connections, Clinton turned the attack into another referendum on Obama, arguing Sanders has called the president "weak" and "disappointing." (It wasn't so clear that Sanders was using those words to describe his own feelings.) She boosted her own credentials by citing her experience "in the situation room" advising Obama, perhaps a nod to the now-famous photo of senior members of the Obama administration awaiting news on the raid that killed Osama bin Laden.

The debate’s setting shouldn’t go unnoticed here; Obama is popular among South Carolina Democrats -- especially the state's large African American population -- and the president beat Clinton in the state in 2008 by almost 30 points. Positioning herself as a continuation of Obama's policies could be a winning strategy in the South Carolina primary.

Clinton had to do something to set herself apart from Sanders in this debate. Sanders's surging poll numbers in both Iowa and New Hampshire had the Clinton campaign worried this week. Will casting Sanders as the anti-Obama stop that surge? It's what Clinton HQ is banking on.