Charlotte—The focus at this Democratic National Convention is on speeches, big speeches.

But one of the most remarkable—and well-received—speeches of the convention was delivered by a nun.

According to some right-wing talk radio hosts and Republican strategists, the Democrats are waging a “war on religion” in general and the Catholic church in particular. They raised such a ruckus when the Democratic platform arrived without a mention of the word “God” that the document was quickly amended.

Yet when Sister Simone Campbell walked onto the stage of the DNC Wednesday night, she was greeted with thunderous applause. The executive director of the Roman Catholic social justice organization Network didn’t really have to announce that she was one of the “Nuns on the Bus.”

Everyone seemed to know that she and other nuns traveled the country this summer to call out House Budget Committe chairman Paul Ryan for proposing a budget that the women argued was at odds with Catholic social-justice teaching. Now that Ryan, who claims his proposals to shred the social safety net are inspired by Catholic doctrine, is the Republican nominee for vice president, Sister Simone is turning up the volume:

Paul Ryan claims his budget reflects the principles of our shared Catholic faith. But the United States Conference of Catholic Bishops stated that the Ryan budget failed a basic moral test, because it would harm families living in poverty.

We agree with our bishops, and that’s why we went on the road: to stand with struggling families and to lift up our Catholic sisters who serve them. Their work to alleviate suffering would be seriously harmed by the Romney-Ryan budget, and that is wrong.

During our journey, I rediscovered a few truths. First, Mitt Romney and Paul Ryan are correct when they say that each individual should be responsible. But their budget goes astray in not acknowledging that we are responsible not only for ourselves and our immediate families. Rather, our faith strongly affirms that we are all responsible for one another.

I am my sister’s keeper. I am my brother’s keeper.

That last pronouncement earned sustained applause from delegates who had packed the Charlotte convention hall to hear former President Bill Clinton make the case for re-electing current President Barack Obama. And the crowd listened intently as Sister Simone told the stories of Americas who are suffering without access to social services and healthcare:

In Cincinnati, I met Jini, who had just come from her sister’s memorial service. When Jini’s sister Margaret lost her job, she lost her health insurance. She developed cancer and had no access to diagnosis or treatment. She died unnecessarily. That is tragic. And it is wrong.

The Affordable Care Act will cover people like Margaret. We all share responsibility to ensure that this vital healthcare reform law is properly implemented and that all governors expand Medicaid coverage so no more Margarets die from lack of care. This is part of my pro-life stance and the right thing to do.

At what is arguably the most pro-choice Democratic convention in history, speaking from a podium where just minutes later reproductive-rights champions such as Sandra Fluke and Planned Parenthood Action Fund President Cecile Richards would present powerful arguments for the right to choose, Sister Simone was not merely welcomed but embraced by the delegates.

Sister Simone recalled the “seamless garment” stance advanced by progressive Catholics such as Joseph Cardinal Bernardin, who argued that to be “pro-life,” one must be opposed to unjust wars and capital punishment and strongly supportive of social welfare programs.

That’s a long way from where Paul Ryan lines up on the issues.

And while she did not come to the Democratic National Convention to make the standard political-endorsement speech, Sister Simone did come to challenge claims by Paul Ryan—and those aligned with him—that they are the defenders of the morality or the values of the nation. “This is what we nuns on the bus are all about: We care for the 100 percent, and that will secure the blessings of liberty for our nation,” explained Sister Simone.

Texting from the floor of the convention, Illinois Lieutenant Governor Sheila Simon wrote: “Sister Simone Campbell just spoke—she was fantastic. She appealed to the best in us—and our responsibility to look after all in our society.”

“The response was so overwhelming,” said Wisconsin State Representative Jill Billings. “Sister Simone was so powerful, I think because she reminded everyone that issues of poverty and neglect are moral issues. Democrats understand that and we need to talk about it.”

Sister Simone echoed that sentiment from the podium.

"Looking out at you tonight," she declared, "I feel your presence combined with that of the thousands of caring people we met on our journey. Together, we understand that an immoral budget that hurts already struggling families does not reflect our nation’s values. We are better than that."