CLEVELAND — Republican attempts to slow Donald Trump’s march to the presidential nomination failed on Monday afternoon — but not before chaos erupted on the Republican National Convention floor as a national audience watched.

A renegade group of delegates — including some from Maine — seeking to force a rules vote that would have embarrassed Trump backers and top GOP officials on the first day of their national meeting was rebuffed in a controversial voice vote, clearing the path for Trump to accept the nomination with no formal challenge.

But it prompted an outcry and triggered a disorderly sequence of events broadcast live on cable news networks and the convention’s official video feed, underscoring deep rifts that continue to plague the Republican Party during a week that was supposed to reflect unity.

Just after 4 p.m., the movement by anti-Trump forces to compel the convention to vote on a set of rules to formalize Trump’s nomination and begin laying out the guidelines for the 2020 elections was denied. While such a measure would have been unlikely to pass, it would have briefly empowered Trump’s foes and slowed the mogul.

“Roll call vote! Roll call vote!” angry delegates chanted, while Trump supporters sought to overpower them with chants of “Trump! Trump!” The Colorado delegation briefly walked off the floor.

Earlier in the day, former New Hampshire Sen. Gordon Humphrey came to the convention floor claiming to be holding a packet of documents with the requisite number of signatures of delegates from 10 states. The Never Trump PAC, a group coordinating the effort, placed Maine among nine delegations whose majority supported the roll call.

But at the podium, U.S. Rep. Steve Womack, R-Arkansas, said many withdrew from the anti-Trump effort, putting three states below a necessary threshold and invalidating the challenge.

Maine was one of those delegations, according to National Committeewoman Ashley Ryan of Portland.

Ryan, who hasn’t endorsed a candidate, but joined the challenge for a more “open” rules process, said the late change came after intense on-the-floor lobbying from the Trump campaign and the Republican National Committee.

She said “large and burly men” pulled her aside to warn her that supporting a roll call would help elect Democratic presumptive nominee Hillary Clinton. Maine lost the required number of votes after staffers cornered five delegates, Ryan said, but it’s unclear who changed their votes.

Maine Senate Majority Leader Garrett Mason, a delegate pledged to U.S. Sen. Ted Cruz of Texas, disagreed with the challenge, saying the convention should rally around the clear nominee.

“Ted Cruz isn’t running for president anymore. I’m sorry about that. I thought he was the best man for the job, but he didn’t make it,” he said. “The process is over, and we’re here to nominate Donald Trump.”

On the sidelines of the event, rifts within the party also were on display as Trump’s top backers aggressively disparaged leading Republicans who have declined to support the mogul for president.

Trump campaign chairman Paul Manafort targeted Ohio Gov. John Kasich and the Bush family, who are skipping the convention, calling them “part of the past” and saying Kasich was “embarrassing his state” by skipping the convention.

For Cleveland, the convention will be a test of its ability to maintain order and safety at a time when tension and deadly violence have erupted between police and African-Americans across the country in recent weeks.

By midday, hundreds of anti-Trump activists had flooded Cleveland’s Public Square with chants and banners condemning the presumptive nominee. Many had walked from Chicago, and others traveled from as far as Texas.

“This isn’t a rally of the biggest names in the world,” said Mick Kelly, a member of the Coalition to Stop Trump and March on the RNC, “but there are real activists here with real struggles.”

BDN writer Michael Shepherd, along with Sean Sullivan, Peter Holley, Jenna Johnson, Louisa Loveluck, Ed O’Keefe, Karen Tumulty and Laura Vozzella of The Washington Post, contributed to this report.