Last Updated Sep 16, 2015 6:14 PM EDT
Donald Trump is not known for sharing the stage with other billionaires, or anyone else. But financier Carl Icahn is one name that keeps cropping up in the Republican presidential contender's campaign, with the investor touted as a potential Treasury Secretary or other emissary in a Trump administration.
Depending on who you ask, Icahn is a brilliant businessman, ruthless "corporate raider" responsible for mass layoffs or staunch defender of the average investor -- or some combination thereof. Whether his mix of skills, not to mention his rep as one the consummate wheeler-dealers of his time, would work in the political realm is subject to debate.
Icahn biographer Mark Stevens, who has spent many hours with the investor and for a period played tennis with him twice a week, calls Icahn both "the smartest person" he's ever met as well as "not a warm person." Icahn, Stevens believes, excels at business negotiations to the point where nobody wants to be on the other side of the table.
"There is a level of humaneness that I know is lacking. In dealing with [Russian President Vladimir] Putin, maybe that's a good thing. Putin has conned Bush and Obama -- he would not con Carl," said Stevens, chief executive at marketing firm MSCO and author of "King Icahn: The Biography of a Renegade Capitalist." "If Trump were president, you'd want Carl on the side to go on missions, but you wouldn't want him to negotiate with North Korea, as it would probably lead to a nuclear war."
Neither Trump nor Icahn returned requests for comment.
Icahn, who came to prominence engineering some of the corporate takeovers that defined the 1980s, including high-profile deals for RJR Nabisco and airline TWA, has made billions as a "shareholder activist," urging investors to overthrow management and pushing large public companies to use their excess cash for dividends and buybacks.
Less flattering accounts portray Icahn as a financial predator prone to acquiring companies with borrowed money, often their own, and selling off any assets that can generate a profit. Among his greatest hits over the decades: Texaco, Viacom (VIA), Phillips Petroleum, Western Union (WU), Motorola and Mylan (MYL). Many of the corporate restructurings that followed in his activist wake included layoffs of thousands of employees.
"Carl made his money by jumping on the backs of CEOs," Stevens said, referring to Icahn's decades of clashes with corporate heads and business rivals, including Trump. "He doesn't listen to anybody. I don't think Carl likes anybody," said Stevens, describing Icahn as a "germaphobe" who refuses to shake hands for fear of catching a fatal disease.
Icahn Enterprises (IEP), a Nasdaq-traded entity controlled by Icahn that represents his investing domain and a collection of businesses, has a market capitalization of $9 billion.
Icahn's recent business ventures includes his efforts to take over the bankrupt Trump Taj Mahal in Atlantic City, New Jersey, a deal made on condition of scrapping health and pension benefits for roughly 1,000 unionized workers. In a blog post penned to the casino's employees, Icahn vowed to "fight any company where we find malfeasance and sweetheart union deals."
Icahn's efforts to take control of the gambling establishment comes more than five years after he and Trump battled in court for 14 months for control of Trump Entertainment Resorts, with Trump winning that round. The court victory paved the way for the company's three Atlantic City casinos to exit bankruptcy for a third time.
The litigation doesn't seem to have left any bad feelings. Trump in June told MSNBC's "Morning Joe" television show that he would "love to bring my friend Carl Icahn" on to run the U.S. Treasury Department. The real estate mogul also mentioned private-equity titan Henry Kravis and Jack Welch, the former CEO of General Electric (GE), as potential Treasury secretaries.
Several months later, at an August rally in Greenville, South Carolina, Trump said he would prefer a dealmaker like Icahn able to get things done as opposed to less capable "nice" people.
Icahn was less than pleased when he caught wind of the comments, which had Trump repeatedly referring to Icahn before saying that most good business negotiators were "vicious, horrible, miserable human beings." Icahn called Trump for an explanation, which prompted Trump, a man not known for public apologies, to tell Reuters that he had not intended to include Icahn in his characterization, and in fact viewed him as among the "nice" 2 percent of strong business negotiators.
That said, Icahn has publicly expressed admiration for Trump's performance at the first Republican debate, so much so, in fact, that he reconsidered the GOP front-runner's offer to appoint him as Treasury Secretary should Trump become president.
"After last night's debate, I decided to accept @realDonaldTrump offer for Secretary of Treasury," the corporate activist tweeted wryly. "The methods of electing our corporate and political leaders have become completely dysfunctional."
The tweet marked an about face from June, when Icahn wrote on his blog: "I am flattered but do not get up early enough in the morning to accept this opportunity."
The question of Trump's fitness for office, including his judgment when it comes to choosing a cabinet, will be in the spotlight at Wednesday night's GOP debate at the Reagan Library in Simi Valley, California.
Stevens expresses skepticism that Trump and Icahn -- both consummate dealmakers -- could get along. Icahn, he said, would negotiate: "I get the Oval Office, I get Air Force One -- I'm not even joking. Trump would say, 'You know what, I can't take this,' " the biographer said.
And despite the bonhomie between the two in recent weeks, another point of contention might be their respective wealth. Trump's worth is usually estimated at between $2 billion and $4 billion, according to published reports. That's small potatoes compared with Icahn, whose fortune Forbes puts at nearly $21 billion.