News Analysis: Trump's nomination acceptance speech crucial to presidential bid

U.S. Republican presidential nominee Donald Trump is gearing up for a big night on Thursday, as he will give a speech that could well make or break his bid to clinch the White House.

The speech to accept the Republican Party nomination at the Republican National Committee is the most important of his life, and Trump needs to hit the ball out of the park in order to unify the party and get the vast majority of rank-and-file Republicans to cast their ballots for him.

"Trump needs to close the convention strong to get a polling bump," Darrell West, vice president and director of governance studies of the Brookings Institution, told Xinhua.

Indeed, Trump is running neck-in-neck against his Democratic rival Hillary Clinton - with Clinton ahead by a hair - and needs a boost in his polling numbers in order to clinch the White House.

"The first two days have been rocky and are not likely to generate a large bounce for him. He could recover from this by giving a strong speech and answering critics who say there is no substance behind his candidacy," West said.

West said that Trump needs to convince party leaders that he has mastered the mechanics of the election and has the organizational skills to wage a credible campaign.

While the brash businessman has shored up many white working class voters who are fed up with what they describe as incompetent and apathetic Washington elites, the candidate also needs to persuade those on the fence to vote for him.

Trump has over the past year grabbed global headlines by making over-the-top statements that have sparked controversy not only with Americans, but also with allies abroad.

The bombastic Trump has compared Mexicans to rapists, and has called for Muslims to be banned from entering the United States, raising red flags with many independent voters and also with establishment Republicans.

Trump has galvanized many white working class Republicans, but has left other Republicans on the fence, and he will need to tweak his tone and rhetoric in Thursday night' s speech in order to win their support.

"Trump will attempt to use Hillary Clinton to unify Republicans around him. That will work with a sizable number of party folks," West said, referring to the tactic of hammering Clinton for her many scandals, such as when she was U.S. Secretary of State.

"But the remaining ones need assurance on policy matters to rally to Trump," he said.

For these individuals who worry that Trump is not a real conservative, he will need to provide substantive clues regarding his views on taxes, trade, immigration, and foreign policy, West argued.

"So far, he has not provided many details on policy issues so this will be a big challenge for him," West said.

Content and tone will be important in Trump's acceptance speech, which needs to be focused and positive. It also needs to convince Americans that he will revive the economy and reestablish America' s standing in the world, which many believe is diminishing, analysts say.

Trump will also need not only to clearly outline his intentions, but must weave into the speech comments that make the candidate seem credible, likable and capable.

Indeed, the brash billionaire is seen by many as hot-headed and impulsive, and viewers will be looking for a candidate who is calm and cool under pressure. Enditem