Scott Adams, the world-famous comic strip artist (Dilbert) and trained hypnotist, recognized Donald Trump's powers of persuasion before nearly anyone else. Now he's expanding his controversial blog posts into a fascinating book about master persuaders like Trump, and how anyone can copy their techniques—for good or for ill.

Soon after Donald Trump declared his presidential candidacy, when most experts dismissed him as a joke who'd be gone before Iowa Scott Adams called Trump a master communicator in the same league as Abraham Lincoln and Steve Jobs. As a student of the art and science of persuasion, Adams recognized Trump's deep toolbox for persuasion. On his popular blog, Adams predicted that Trump could go all the way. The public response was ridicule, scorn, and even calls to boycott Dilbert. But ultimately, Adams was right and his critics were wrong.

So what did Adams see that the pundits missed? The short answer is the power of...