Even as the GOP establishment and leading conservative groups are starting to warm to Donald Trump, a large and important segment of the Republican base has been conspicuously quiet -- corporate America.
Wall Street and the nation's business community have historically been dependable backers of the Republican Party, whose core values of reducing taxes and government regulation are most closely aligned with their own pro-business growth priorities.
This election year the choice should be particularly easy between Trump, a lifelong businessman, and a Democratic Party that has been pushed by Sen. Bernie Sanders to adopt an unusually harsh anti-business tone, calling for the breakup of big banks and sharp tax increases for the wealthy.
Yet with the exception of a relatively small number of corporate leaders, such as oil tycoon T. Boone Pickens and casino mogul Sheldon Adelson, the business world by and large has been lying low, unwilling to associate publicly with a man whose highly contentious positions and freewheeling talk have raised concerns among a lot of ordinary Americans.
Over the course of his unexpectedly successful campaign, Trump has been condemned for proposing a ban on Muslims entering the U.S., making offensive remarks about women's looks, and saying Mexico was sending rapists and other criminals across the border.
Moreover, Trump's economic policies have startled many in business, and his vague and sometimes flip-flopping positions have left executives scratching their heads. Many say they don't know what to think of Trump's stands, or just how much his stated views should be taken at face value.
Trump, for example, has walked back on his proposal to cut taxes for the wealthy, and he has gone back and forth on whether he would support an increase in the federal minimum wage, currently $7.25.
Several times he's warned against investing in the stock market, speaking of a "bubble." He angered Silicon Valley entrepreneurs by suggesting the tech industry is heading for a crash and then calling for a boycott of Apple after the iPhone maker refused to help the FBI hack into a terrorist's device.
So far none of Trump's policies or bombastic statements seem to have shaped financial markets, suggesting that investors and corporate leaders may not be taking his candidacy very seriously. That will start to change, however.
"If I were a large firm doing trade in Mexico or China, I would be nervous right now," said Nicholas Bloom, a Stanford University economics professor who tracks the effects of uncertainty on the economy.
Trump has called for a 45% tariff on Chinese goods, the building of a wall across the southern border and deporting of 10 to 11 million immigrants living in the country illegally -- policies that many experts agree would be difficult to implement and disastrous for the American economy.
"My prediction is that in the third or fourth quarter, if things look like it'll be a close run between them, and he continues with his extreme comments, I could see there being a lot of volatility and fear in the markets," Bloom said.
Republican Party officials, including those working on corporate sponsorship of the GOP convention in July, have sought to allay business leaders' concerns about Trump. Lindsay Walters, spokeswoman for the Republican National Committee, insists that the party's platform will be "crafted, voted on and approved" by elected convention delegates, not necessarily reflective of Trump's more controversial campaign promises.
Representatives of a number of Fortune 500 multinational firms, including Citigroup and Walmart, declined to comment on Trump.
Coca-Cola, for one, has sharply cut back its donation for the GOP convention this year from 2012 levels, although the company notes that it is nonpartisan and does not endorse any party or presidential candidate. Some other firms also appear to be making what look to be cold calculations about what's best for their business interests.
Although GOP convention fundraising officials say they're ahead of where they were in late May compared to 2012, business leaders' embrace of Romney was clearly more evident than what they've shown for Trump so far. That's troubling for the Trump campaign since these business elite are able to bundle tens of millions of dollars in financing, said Reed Galen, a veteran GOP strategist.
"It's such a much more edgier, rougher campaign that it gives corporations pause to get involved," Reed said.
Thomas Donohue, president of the U.S. Chamber of Commerce, the largest lobbying organization for businesses, said he wasn't hearing a lot from his members about Trump. But what he has heard, he said, was "mostly concern," including questions like, "Who is this guy? What do we know about him? How will he behave?"
While they wait for answers, Donohue said "businesses are sitting on their hands and sitting on their cash ... watching very carefully where they're going to make their investments and when they're going to make them. And I think all of that is a reality that they're trying to learn who he is and what he will eventually do."
John Rodenrys, 72, a longtime California Republican and former rocket scientist, talks like a man who wants to support Trump. But he is hesitant knowing that the real estate magnate has broken with GOP orthodoxy, for example, in bashing the massive Pacific free-trade agreement that is pending. Rodenrys strongly supports it.
"It's quite a conundrum right now," said Rodenrys, who co-founded Leading BioSciences, a biotech firm in Solana Beach.
Then there are Trump's shoot-from-the-hip remarks, like suggesting that the U.S. could deal with the huge national debt by printing more money or renegotiating with its creditors -- something Trump later clarified as possibly buying back U.S. bonds at a discount. Some thought Trump's initial remarks were a joke, although it was hardly a laughing matter to investors and business people.
"We're not Argentina, we're not Paraguay. We need to honor our debts," said Drew Greenblatt, president of Marlin Steel Wire Products, a 31-employee firm in Baltimore, and executive committee member of the National Assn. of Manufacturers. Greenblatt wouldn't say whether he would support Trump, but says he is disappointed that the likely GOP nominee, as well as his Democratic rival, Hillary Clinton -- whose husband, President Bill Clinton, pushed through NAFTA -- are both attacking trade.
"I'm against anybody who wants to smash trade and use it for political points," he said.
Many Republicans, in business or not, think Trump will back off from his inflammatory remarks and move toward the center on positions that are more politically acceptable. And as Trump's nomination looks all but assured, party elites and some stalwart conservative groups, including Ralph Reed's Faith & Freedom Coalition and the Susan B. Anthony List, an antiabortion group, have embraced Trump as still better than Clinton.
Some business people and analysts point out that Ronald Reagan was once considered too doctrinaire and risky, although many Republicans today hold him out as a beacon of the party.
Trump has argued that his business experience makes him uniquely qualified to be president. But for all of his success building luxury hotels, golf resorts and other ventures -- Trump also has had notable bankruptcies -- the business world isn't convinced that his knack for deal-making will make him a good president. A lot of business people do not seem to view him as one of their own.
"He's met a payroll, he's juggled finances and managed employees, but I don't see him so much as a businessman. I think he's more of a reality TV star," said Chris Rupkey, managing director at Union Bank in New York.
"Wall Street appreciates his candor. It's refreshing," Rupkey said. But he added: "We don't know what's going to stick. He's thrown a lot of things on the wall."