WASHINGTON — Vermont Sen. Bernie Sanders called on supporters to spark a “political revolution” for his 2016 Presidential candidacy, offering a rallying cry of “enough is enough” on a video simulcast to events across the country.

The Sanders campaign said more than 105,000 backers attended 3,500 meetings in homes, coffee shops, union halls and town squares on July 29, an effort to spread the message of his insurgent bid for the Democratic presidential nomination.

“The American people are saying loudly and clearly: Enough is enough,” he said, standing before a bank of video cameras set up in a crowded Washington apartment. “Our government belongs to all of us and not just a handful of billionaires.”

Despite the enthusiasm for Sanders, former First Lady, U.S. Senator and Secretary of State Hillary Rodham Clinton appears unlikely to face a formidable Democratic opponent in the primary campaign, unlike in 2008 when she lost the nomination to Barack Obama.

Whoever gets the nomination faces the winner of a crowded Republican primary field that could feature as many as two dozen candidates.

Sanders made an impassioned argument for building a single-payer health system, tackling income inequality, eliminating student debt, addressing institutional racism, expanding family leave and raising a “starvation minimum wage.”

“Bernie Sanders alone as President of the United States is not going to solve all these problems,” he said, reading off a yellow legal pad with handwritten notes. “But when we stand together there is nothing, nothing, nothing that we cannot accomplish.”

Sanders has ridden the populist wave surging through the Democratic party, attracting large crowds to rallies across the country with his unapologetically liberal message.

In recent weeks, he’s seized on Hillary Rodham Clinton’s refusal to say whether she backs the Keystone XL pipeline and the Trans-Pacific Partnership — both opposed by key segments of the Democratic base.

Sanders’ campaign is trying to emulate the model used by President Obama, who mobilized supporters against Clinton in the 2008 primary through an expansive organizing effort focused on networks of personal contacts.

Larry Cohen, a former President of the Communications Workers of America, encouraged backers to volunteer for the campaign — and sign up others to make calls, knock on doors and contribute.

“We’re part of a historic moment but our job is to build a historic movement,” he told the cameras. “Solidarity.”

Sanders’ unexpectedly strong showing has not gone unnoticed by Clinton’s team. Her aides have signaled that they consider Sanders to be a legitimate challenger who will be running for the long haul, noting the $15.2 million he’s raised, largely from small donors, in the first three months of the race.

They believe he will find a measure of support in Iowa, where the caucus system typically turns out the most passionate voters, and New Hampshire, given Sanders’ many years representing neighboring Vermont in Congress.

(LISA LERER)