Philadelphia—When the Democrats Abroad delegation delivered the majority of its votes to Vermont Senator Bernie Sanders during Tuesday night’s Democratic National Convention roll call, an amiable 82-year-old gentleman from the English county of Oxfordshire stepped to the microphone to say a brief word about his parents.

“I want to bring before this convention the names of our parents: Eli Sanders, Dorothy Glassberg Sanders. They did not have easy lives, and they died young. They would be immensely proud of their son and his accomplishments. They loved him,” said Larry Sanders, as he teared up.

“They loved the New Deal of Franklin Roosevelt and would be especially proud that Bernard is renewing that vision. It is with enormous pride that I cast my vote for Bernie Sanders.”

Across the hall where the roll call was taking place sat Bernard Sanders, with tears welling in his eyes.

Amid all the frenzy of a national convention, this was a moment of human connection between a proud older brother and a younger brother whose presidential run had secured 13 million votes, won 23 primary and caucus contests, brought almost 1,900 delegates to this week’s convention, and forced the Democratic Party to embrace progressive platform planks and rules changes that might just democratize the Democratic Party.

“This is the start of something big in American politics,” Larry Sanders said when we discussed the campaign Bernie Sanders waged for the 2016 Democratic presidential nomination—and the changes that he believes will extend from that campaign. Echoing the sentiment of the 1,865 Sanders delegates who cast their votes for the senator Tuesday night, the older brother said, “Bernard did not win the nomination, but you cannot stop the movement that has begun here.”

Larry Sanders, who moved to Britain in the late 1960s (around the time his little brother moved to Vermont), is no casual observer of political movements. Bernie Sanders credits his older brother with introducing him to radical ideals when they were coming of age in Brooklyn. And Larry Sanders, a retired university lecturer and social worker, has been active in electoral politics in his own right.

A longtime activist with with Britain’s Labour Party, he switched to the Green Party of England and Wales when former British prime minister Tony Blair was moving Labour away from its historic socialist moorings.

Elected as a Green to the Oxfordshire County Council in 2005, the elder Sanders served for eight years as an outspoken champion of expanded social services and access to health care. He was, and is, an ardent critic of the sort of austerity cuts that his brother has campaigned against in the United States. In 2015, Larry Sanders was a Green candidate for Parliament and, this year, he took over as national spokesperson on health issues for the party that asks voters to “Imagine a political system that puts the public first. Imagine an economy that gives everyone their fair share. Imagine a society capable of supporting everyone’s needs. Imagine a planet protected from the threat of climate change now and for the generations to come.”

After Bernie Sanders won the Democrats Abroad voting in March, with 69 percent of the vote, Larry Sanders was chosen as an at-large delegate on a slate backing his brother.

So Larry Sanders made his way to his first American political convention. He came with a dual mission—to back his brother for the nomination, and to back his brother’s call for the defeat of Donald Trump.

“Trump represents virtually everything that Bernard is against in politics,” said Larry Sanders, who was in the hall Monday night to cheer the speech in which his brother endorsed Democratic nominee Hillary Clinton for the presidency while at the same time declaring, “Together, my friends, we have begun a political revolution to transform America and that revolution—Our Revolution—continues. Election days come and go. But the struggle of the people to create a government which represents all of us and not just the 1 percent—a government based on the principles of economic, social, racial and environmental justice—that struggle continues. And I look forward to being part of that struggle with you.”

It was exciting to hear the thunderous applause for his brother Monday night, and it was exciting to speak—“for about 40 seconds”—Tuesday night. But the convention has been bittersweet for the older brother of the candidate who took on the billionaire class.

“I am sad,” said Larry Sanders. “I think Bernard would have made a difference in world history.”

Then Larry Sanders smiled, as older brothers do.

“I think he’s already made quite a difference,” he added. “But I would have liked Bernard as president.”