"I spent a lot of time last week being outraged by what's happening in Flint, Mich., and I think every single American should be outraged," Clinton said in her closing statement, bringing up an issue that had not been discussed all evening in Charleston, S.C.

"We've had a city in the United States of America, where the population, which is poor in many ways, and majority African-American, has been drinking and bathing in lead-contaminated water," she said to growing cheers.

"And the governor of that state acted as though he didn't really care. He had requests for help that he basically stonewalled."

"I'll tell you what," Clinton said. "If the kids in a rich suburb of Detroit had been drinking contaminated water and being bathed in it, there would've been action."

Clinton seemed to take credit for Snyder's eventual response, saying that she sent her top campaign aide to talk to the mayor of Flint "to see what I could do to help."

"And I issued a statement about what we needed to do. And then I went on a TV show and I said it was outrageous that the governor hadn't acted, and within two hours he had."

"A man who acts that irresponsibly shouldn't stay in power," Sanders said to cheers.

Liberal filmmaker Michael Moore, a Flint native, tweeted:

THANK YOU HILLARY!!!!!!!! FLINT THANKS YOU!!!!!!!!!!!!!! ONLY YOU MENTIONED IT!!!! AND U SPOKE THE TRUTH! BIGGEST APPLAUSE OF THE NIGHT! — Michael Moore (@MMFlint) January 18, 2016

Moore also gave Sanders credit:

And yes, thank you Bernie. Yesterday you became the first presidential candidate to demand the Governor's resignation. — Michael Moore (@MMFlint) January 18, 2016

Snyder tweeted in response to the attacks: