US Republican presidential nominee Donald Trump continues to pile insults on rival Hillary Clinton recently, but experts said that could hurt him more than help him.

Recent days have seen Trump ramping up on the insults against Democratic nominee Hillary Clinton, even referring to her as "the devil." But while experts said the brash businessman should be focusing on Clinton's policy blunders, he continues to engage in name calling.

"Trump's insults reinforce the perception that he is ill-tempered and not well-suited for the presidency," Darrell West, vice president and director of governance studies of the Brookings Institution, told Xinhua News Agency.

It would make more sense for Trump to criticize her policies rather than calling her names, West said.

"That would help him argue that she has a failed vision and shouldn't be elected to the highest office in the land," he said.

US voters are more accepting of differences on the issues because that is a legitimate part of electoral discourse. But Trump goes too far and makes himself look bad in the process, he added.

Indeed, critics say Trump's major fault is that he's still preaching to the choir - the blue collar white males who put him through the primaries, with whom Trump struck a chord with over-the-top comments.

But now that Trump has already got the white working-class male vote in the bag, analysts say he should be stepping forward and broadening his horizons.

Trump needs to understand that appealing to a general electorate of 130 million people is different than a Republican primary audience of 20 million people, West said.

"The former requires a different style of argumentation than the latter," West said.

One of the issues Trump might focus on is Clinton's recent e-mail scandal, which overshadowed last week's Democratic National Convention in Philadelphia.

Clinton has also been embroiled in another controversy in recent weeks. Leaked e-mails from the Democratic National Committee showed that it tried to tip the scales in favor of Clinton to win against her opponents, mainly Democratic rival Bernie Sanders, in the primaries.

Sanders' supporters said the e-mail scandal showed that the Democratic Party rigged the system to allow Clinton to unfairly grab the party's nomination for president.

Christopher Galdieri, assistant professor at Saint Anselm College, said that Trump is not converting anyone with his insulting attacks on Clinton.

"It appeals to his primary voters but they are already with him. It doesn't help him with skeptical Republicans," Galdieri said.

Julian Zelizer, professor of history and public affairs at Princeton University, told Xinhua News Agency that nothing Trump is doing now is working very well.

Clinton's polls are getting better and better, more Republicans are saying they will vote for Clinton, and the media has really turned against Trump in a significant way, Zelizer noted.

He said Clinton doesn't have to constantly respond to Trump's insults because this will provide voters "with a feel of stability and steadiness."

Galdieri said Clinton's best move is to give Trump ample room to keep shooting himself in the foot, while she keeps a steady hand.

"In this regard I think picking Tim Kaine, an amiably boring and experienced figure from a key state, will prove to be one of the smartest moves of her campaign," Galdieri said of Clinton's running mate, a senator from the state of Virginia.

The author is a writer with the Xinhua News Agency. The article first appeared on Xinhua. opinion@globaltimes.com.cn