The Republican National Convention that will nominate insurgent Donald Trump for president opened Monday in a display of division that forced party leaders to put down a floor fight triggered by the billionaire mogul's opponents.

The chaotic scene played out in mid-afternoon, long before network television stations were set to go live with Melania Trump's maiden turn on the national stage in support of her husband, who planned to attend his wife's address. The theme of the day, ironically, was law and order.

A group of delegates -- including those from Colorado -- , mostly opposed to Trump's nomination, tried unsuccessfully to force a roll-call vote on the the convention rules. Pro-Trump delegates sought to shout down the protesters -- led by Sen. Mike Lee of Utah and former Virginia attorney general Ken Cuccinelli -- whose effort could have delayed the proceedings by hours on the convention's opening nights.

At one point, the podium of the convention was empty, leading Lee to say the convention had fallen into disarray on its first day, which was scheduled to emphasize law and order.

"I've never seen the chair vacated like that," Lee said, calling the situation "surreal."

Never Trump delegates chanted "roll call vote!" and "point of order!" from the floor, seeking to force the issue. A similar effort failed last week before the convention rules committee.

Despite the flurry of activity by Trump's opponents, their attempt was quickly stymied. Some GOP activists, such as conservative analyst Bill Kristol, said it resembled the strong-arm tactics of Russian President Vladimir Putin.

Cuccinelli, a leading supporter of a roll call vote, threw his credentials to the floor and walked off, claiming party leaders rammed through the voice vote in spite of petitions calling for a separate ballot.

"They just blatantly violated the rules," he told reporters.

Monday’s theme is “Make America Safe Again," and GOP Chairman Reince Priebus, after banging the opening gavel, began the proceedings with a moment of silence for fallen police officers. The convention then rolled into a mix of patriotism, music and routine business before the anti-Trump outburst.

The prime-time lineup includes a lengthy mix of speakers headlined by Trump's wife, Melania, and Trump's camp says the candidate will break with tradition and step to the podium to introduce her.

Others in line to speak include Duck Dynasty star Willie Robertson, Scott Baio, known for his role as Chachi on Happy Days, former Texas governor Rick Perry, survivors of the attack on the U.S. diplomatic mission in Benghazi, immigrant activists and former New York mayor Rudy Giuliani.

Trump claimed the GOP throne with a shoestring budget but an unrelenting social media campaign, pounding challengers into submission with blistering criticism. His campaign started with two simple premises — build a wall to keep immigrants out, and make America great again.

It worked.

He roared to the top of the Republican polls and stayed there. A wide swath of Americans who felt the economic recovery was passing them by and that Washington was out of touch bought in. Plenty of icons of his own party didn't, and the list of GOP dignitaries skipping his four-day Cleveland lovefest is impressive, including the last two Republican presidents and the party's nominees from 2008 and 2012.

Even John Kasich, governor of the state hosting the convention, passed on the party. Trump's campaign manager accused Kasich, the last challenger to drop out of the GOP presidential race, of "embarrassing" his state.

No matter. Trump's lineup of speakers includes plenty of family members, veterans, business people, entertainers and a smattering of top-drawer Republicans, including House Speaker Paul Ryan and even bitter rival Ted Cruz.

Melania Trump's appearance could be crucial. It will be the first time many Americans hear the Slovenia-native's voice. The first impression may be crucial for Trump, who is struggling to lure female voters. His 34% support among women in an ABC News/Washington Post poll released Sunday is a record low — lower than the level of female support on Election Day for any Republican presidential candidate since World War II.

But the polling news for Trump isn't all bad. A Monmouth University poll released Monday says Hillary Clinton, the presumptive Democratic nominee, holds a 3 percentage point lead among registered voters and a 2 point lead among those most likely to vote. Last month, Clinton led by 6 points with registered voters and 7 points among likely voters.

There was some dissent on the Cleveland streets. The first major test for police and demonstrators was largely uneventful, as between 200 and 300 people representing the Coalition to Stop Trump rallied and then marched through downtown, guided by about 40 police officers on bicycle.

While loudly chanting anti-Trump slogans, the march immigrant rights supporters, the Black Lives Matter movement and Muslim rights advocates drew nowhere near the thousands organizers had predicted.

“It’s annoying,‘’ said Mike Magee, part of the red, white and blue-clad Texas group watching the protest from a distance as they boarded a bus. “I’ve got 100 percent trust in local police and federal law enforcement to keep things safe.’’

On Tuesday, the convention will focus on Indiana Gov. Mike Pence. He will formally be chosen as the vice presidential candidate. On Wednesday, the ceremonial roll call of the states will install Trump as the party's candidate. And the climax is Thursday, when Trump formally accepts the nomination.

A few days later, attentions will turn to Philadelphia, the Democratic National Convention and Hillary Clinton. Then the three-month race to the White House begins in earnest.

Contributing: Kevin Johnson, Herb Jackson, Carl Weiser and Rick Hampson, USA TODAY Network