The moment came early on, while she was responding to an audience member's question about whether the campaigns were modeling good behavior for children. Without missing a beat, Clinton used the devastating tape unearthed by NBC News and the Washington Post of Trump bragging about sexually assaulting women, and then pivoted to talk about its broader importance.
In one moment, she wove together what's been so disconcerting for many Americans about Trump's political rise, and all the people he's managed to denigrate along the way — Mexican immigrants, people with disabilities, prisoners of war, and the list goes on.
"We've seen him embarrass women on TV and Twitter. We saw him after the first debate, spend nearly a week denigrating a former Miss Universe in the harshest, most personal terms. So, yes, this is who Donald Trump is. But it's not only women and this video that raises questions about his fitness to be our president. Because he has also targeted immigrants, African-Americans, Latinos, people with disabilities, POWs, Muslims and so many others."
Then, Clinton went for the jugular:
"This is who Donald Trump is. The question for us, the question our country must answer is that this is not who we are. That's why, to go back to your question, I want to send a message — we all should — to every boy and girl, and indeed to the entire world. That America already is great, but we are great because we are good. And we will respect one another. And we will work with one another. And we will celebrate our diversity. These are very important values to me, because this is the America that I know and love. and I can pledge to you tonight, this is the America that I will serve if I'm so fortunate enough to become your president."
The moment was reminiscent of 2008's presidential campaign, when then-Senator Barack Obama was embroiled in a controversy about his longtime pastor, Jeremiah Wright, who'd been targeted by conservatives for allegedly stoking anti-American sentiment.
Obama went to Philadelphia, where the country's founding fathers signed the Declaration of Independence in 1776, and delivered what was formally known as a speech called "A More Perfect Union." But unofficially, the address — which you can read in its entirely at the New York Times — was dubbed the "race speech," for its cogent examination of how race and racism work in the United States, and how they'd worked thus far in that year's presidential campaign.
Moments like these are hugely important in presidential campaigns. They become the narrative arcs of our political history. And at a moment of unprecedented upheaval in the Republican party, Clinton's words serve to remind us that presidential campaigns are, at their core, moments where Americans look to leaders who can articulate their hopes for a better future.