News Analysis: U.S. Republican front-runner Trump has yet to explain holes in policies

- While Republican presidential front-runner Donald Trump has emphasized how he would revive the sluggish economy and strengthen U.S. foreign policy, he has still not clarified how he would achieve these goals, experts said.

Trump has flip flopped on a number of issues and even contradicted himself on numerous occasions, which could lend fodder to rival candidates, experts said.

The brash U.S. business tycoon has over the past months made numerous campaign promises, such as vows to boost manufacturing and bring the United States out of the state of economic malaise the country has been in since the 2008 economic downturn.

"Trump does have a problem in the general election between his policy statements and personal behavior," Brookings Institution's senior fellow Darrell West told Xinhua.

"He rails against illegal immigration and foreign countries but relies on labor from those countries. He talks about bringing jobs back from Mexico, but has outsourced work to those places," West said.

Trump has bandied about soundbites, saying he wants to "make America great again," but critics question how exactly he will do this and in what areas.

Those discrepancies may lend fodder to likely Democratic nominee Hillary Clinton, if Trump is to face off against her.

"Democrats will argue that he is a hypocrite who changes his positions all the time. They will portray him as a weather vane that shifts with the slightest breeze," West said.

One policy prescription that has many analysts scratching their heads is Trump's proposed wall on the southern U.S. border which he intends to build in order to keep out illegal migrants from Mexico and other Latin American countries, many of whom have entered the United States through the porous U.S.-Mexican border by foot.

While Trump said he would get Mexico to pay for the wall, critics ask how exactly Trump would pull off such a diplomatic feat.

In a recent nationally televised Republican debate, Fox News moderator Megyn Kelly presented a video showing Trump allegedly contradicting himself on issues ranging from whether to allow refugees from the Middle East to enter the U.S., the U.S. war in Afghanistan, and whether former U.S. President George W. Bush lied about weapons of mass destruction in the lead up to the U.S. war in Iraq.

Kelly then asked pointedly: "You've changed your tune on so many things, and that has some people saying: what is his core?"

Trump replied that it has a "very strong core," but added that he is "flexible."

Julian Zelizer, professor of history and public affairs at Princeton University, said that the flip flops and inconsistencies could hurt Trump.

Still, Zelizer said that at times, sending mixed messages to various groups -- telling each what they want to hear -- could actually help Trump, as it has helped some candidates in past elections.

"Part of his strategy in doing this has been to send mixed signals to different constituencies so voters can read what they want in him," Zelizer told Xinhua.

"Sometimes candidates, including both Clintons, have embraced this style successfully. So while everyone says flip-flopping is devastating politically, some candidates use this to their advantage," he said, referring both to the current Democratic front-runner Hillary Clinton and her husband, former U.S. President Bill Clinton.

Critics say U.S. media has failed to take Trump to task for what critics often bill as unworkable policies, as reporters are often fixated on Trump's outlandish comments and personal insults toward other candidates, rather than analyzing the policies of the candidate who may well clinch the Republican Party nomination. Endit