- The convention is Trump's chance to broaden his appeal
Cleveland (CNN)It's time for the reality star to show he's ready for prime time.
The Republican National Convention in Cleveland, culminating in the party nominee's key note address on Thursday night, will require a set of political multi-tasking skills far beyond those so far demonstrated by Donald Trump.
The high stakes political jamboree should begin to answer a fundamental question of the 2016 election: whether a campaign anchored almost exclusively on Trump's hulking public persona and dominant ego can perform as well on the national stage as in the rough and tumble of Republican primary politics.
"Can he move himself from being primary candidate who sometimes comes across as the host of a reality TV to show himself as a possible President of the United States?" said Bill Lacy, a veteran GOP hand who worked for Ronald Reagan in the White House and on the presidential campaigns of Bob Dole and George H.W. Bush.
Trump enters the convention under pressure to show more discipline, gravitas, and sobriety in his freewheeling campaign ahead of an election in which a new CNN/ORC poll shows he trails Democrat Hillary Clinton by five points. The convention is a once-in-a-campaign chance for Trump to show there is more to him than stroking his own ego, and that he understands the aspirations and fears of an uneasy nation in a world seemingly spinning out of control and has the temperament to be commander-in-chief.
The heightened sense of public anxiety was stoked again on Sunday as the nation was once again processing tragic news following the killing of three police officers in Baton Rouge, Louisiana, in an apparent ambush.
If the story at the end of the week is the familiar one of an unruly Trump making the week all about him and in the process stepping on his own message, the convention will go down as a missed opportunity and create an opening for the Democrats.
For most nominees, the party conventions serve as an introduction to voters who will decide the general election in November.
But Trump's long-runningreality show "The Apprentice" made him and his personality part of the national conversation for years. His genius at publicity, a hyperactive Twitter account and a life lived in the tabloid glare also means he needs no introduction.
Still, as he seeks to broaden his national appeal, Trump's public persona could do with some reshaping — since the hardline personality that was electoral gold in the primary threatens to repel many more moderate voters.
Trump's unique unorthodox political style, rambling speeches and boastful swagger have often detracted from the message his campaign is trying to implant in the public mind. His inability to repeatedly deliver a concise message weakened Republican attacks on presumptive Democratic nominee Hillary Clinton over her email controversy.
And on Saturday, Trump's self-indulgent speech tarnished his roll out of his vice presidential nominee, Indiana Gov. Mike Pence.
The question now is whether Trump has the capacity and discipline to hammer home the message party officials have sketched ahead of the convention -- namely that the GOP represents change and the Democrats stand for the same old, same old.
"What we're going to offer is a different vision, a different way forward, a different set of excitement that's never been seen at a political convention before," Sean Spicer, the RNC's chief strategist on CNN's "New Day" on Friday.
Such is Trump's unpredictability and unconventional approach to politics that many seasoned Republican Party observers question whether he can put his own ego aside to deliver that message.
"This convention is a great challenge and opportunity for Trump," said Lacy.
"There are a lot of us out there who aren't sure of him — lots of people in the Senate and the House who aren't sure of him."
The billionaire showed he understands that task by candidly admitting Saturday that he chose Pence because people were telling to unite the GOP.
But there is more to do. Key sectors of the conservative movement -- which the billionaire needs to show up in November -- are unsure which version of Trump will show up.
"I have no idea -- he is so unorthodox," said Mark Meckler, a prominent early leader of the Tea Party movement who now heads the group Citizens for Self-Governance.
There is one sure fire way that Trump could unite the party behind him and take the focus off his own liabilities -- with a ruthless denunciation of Clinton, Meckler said.
Grass-roots activists "literally don't believe she is qualified to be president and believe she could have charged with crimes as opposed to running for president," Meckler said.
But committed GOP voters alone will likely be insufficient to help him capture the White House in November. So he must make a case to a broader swath of Americans than those who backed him in the GOP primary.
That means projecting a steadier picture of his character, temperament and intellect to win over voters who may have decided that they could never vote for Clinton but remain concerned about his suitability to be President.
Dr. Bart Rossi, a psychologist and commentator who studies the motivations and behavior of politicians, said Trump needs to change his manner of interacting with his audience.
"He doesn't stay focused. He seems to be someone who is projecting himself as someone who is extremely egotistical -- who has no consistency and no stability," Rossi said. "That lack of stability makes a lot of people nervous."
So how can Trump smooth the edges of his public persona and reassure people who don't yet see him as a potential president?
Trump's family will play a key role here in their speeches to the convention. His daughter Ivanka and sons Eric and Donald Jr. will be especially important in building a more sympathetic picture of a man the Clinton campaign is portraying as temperamentally unfit to sit in the Oval Office.
Lacy said Trump must convince Americans that the experience and decision-making skills acquired in a lucrative real estate career are applicable to the presidency. Then he has to convince them that he can evolve from the bully of the Republican primaries to fill the exacting demands of the presidency.
And Trump needs to display more personal magnetism than he has thus far, Lacy said.
"I keep seeing all this anecdotal information that in person he is a delightful person -- that he is courteous, that he is agreeable — that has not come across in the campaign or in the tweets," Lacy said. "He needs to get that story out there."