What leaders today embrace some of the tenets of Transcendentalism?

One leader who embraces the Transcendental concept of Individualism as promoted in Ralph Waldo Emerson's essay "Self-Reliance" is Donald J. Trump. Another leader in the business world is Sir Richard Branson, who has also fought against imitation like Emerson did.
There is no question that Trump is his own person and believes in Emerson's motto, "Trust thyself." For instance, during one interview with Bill O'Reilly, O'Reilly cautioned Trump regarding broaching certain topics in his campaign rallies and doing certain actions. Trump's response was to say, "Bill, I'm a winner." He trusted himself and his ability to win in the Republican debates, and succeeded in becoming the party's nominee for President of the United States.
Another leader in the recording industry, airlines, and spacecraft, who is very self-reliant and

does not keep pace with his companions. . . because he hears a different drummer (Henry David Thoreau)

is Sir Richard Charles Nicholas Branson, an entrepreneur whose estimated net worth is $5.2 billion. Knighted at Buckingham Palace for "services to entrepreneurship," Branson began by not keeping pace with others who had recording companies because he signed unknown and controversial music groups.
When he was just sixteen, Branson began a magazine named Student. In 1970, Branson began a mail-order record business. In 1972, he expanded to a chain of record stores called Virgin Records, which later became known as Virgin Megastores. They were the first companies with the name Virgin; from then on, his other ventures carried this name, such as his airlines and spacecraft: Virgin Atlantic Airways began in 1984 and Virgin Mobile launched in 1999.
As a youth, Branson was told he would either become very wealthy or end up in prison. The young Branson felt, like Emerson, that a man should trust himself:

To believe your own thought, to believe what is true for you in your own private heart is true for all men—that is genius.

Businessmen Donald Trump and Sir Richard Branson possess this "genius." They reject "the opium of custom," as Emerson phrases the adherence to what is expected. Trump built in Manhattan when his father warned him against doing so; Branson sponsored musical groups when no one else would. Both men believed in the mantra of Transcendentalism: "Trust thyself."