“I am a dealmaker.”

Donald Trump’s clarion call is resonating strongly in the show business community -— an assemblage that usually leans to the left. “He follows his gut,” one CEO confided to me approvingly. Hollywood’s power elite has always admired “gut players,” from Rupert Murdoch going back to Warners’ Steve Ross. Strategy plays well at board meetings, they note, but at decision time, instinct rules.

I was reminded of these realities last week while listening to speeches at a memorial honoring one of Hollywood’s legendary dealmakers, Merv Adelson, who died at the age of 85. Adelson was the ultimate gut player, and the fact that he died penniless at the Motion Picture Home sent a sobering message to the power players paying their last respects.

Having started as a grocery store owner in Las Vegas, Adelson forged a TV and movie monolith sufficiently imposing that Warner Bros. laid out $1.2 billion to acquire it in 1989. It was a deal Trump would have admired; it gave Warners enough heft to trigger a follow-up merger that created Time Warner. Adelson became vice chairman of the corporate giant, with hundreds of millions to play with.

He played badly. “Only Merv could have gone from rags to riches to rags,” lamented his longtime friend, Irwin Molasky.

Adelson’s shy, soft-spoken demeanor masked a fierce ambition. Starting Lorimar in 1969 with his bombastic then-partner Lee Rich, Adelson soon found himself with a cache of hot TV shows like “The Waltons,” “Dallas” and “Eight Is Enough.” Coveting the company of stars, he shifted his dealmaking focus to movies, but with a novel business plan — at least novel for the time. While the studios put millions at risk, under Adelson’s scheme, the budgets of Lorimar films would be covered by TV and foreign pre-sales. Adelson effectively invented the American Film Market, inviting scores of foreign distributors to his La Costa resort to see his films and, he hoped, make offers. He skillfully side-stepped questions about the resort’s finances: Were the Teamsters or even shadier Las Vegas investors involved? His marriage and remarriage to Barbara Walters fortified his image as a global celebrity.

When I was brought aboard by Adelson to preside over his film slate, I was unaware that Lorimar had already produced several of these pre-sold pictures — projects that unfortunately no distributor wanted to release. While Adelson loved making movie deals, it seemed, his taste in films was at best idiosyncratic. He had little enthusiasm for Hal Ashby’s “Being There,” which Lorimar produced during my tenure, nor for “An Officer and a Gentleman,” which my successor, David Picker, fostered (he shifted the project to Paramount, retaining 10% of the gross for Lorimar).

Despite his movie setbacks, Adelson forged ahead on the corporate dealmaking front. He skillfully negotiated a merger with the syndication giant Telepictures in 1986, then three years later closed his mega-deal with Warner Bros., which coveted not only the product but also the executive talent that Lorimar had mustered — Leslie Moonves, Peter Chernin and Bruce Rosenblum among them. Lorimar had also built a formidable video business under Warren Lieberfarb.

With his Warners deal, Adelson was sitting on top of the world — but he wanted more. The advent of the dot-com boom seemed preordained to appeal to his nature as a wheeler-dealer, but his choices went consistently astray. As his fortune dwindled, the value of his Time Warner shares also cratered, because of the AOL debacle. Friends were concerned over his decline, but no one realized its magnitude until it was too late. The power players who had once admired his panache did not step up to help repair the damage. The dealmaking king ultimately became a forgotten man.

And, no, Donald Trump never phoned in his advice.