If you look at the elements of swagger that were listed in a previous post, it becomes obvious why Reagan was so successful. He was a large, powerful, athletic man with a celebrity background, a boatload of self-confidence, and no doubts about his ideology. He met all of the tests in my post in spades. Republicans loved him, and still do.
Donald Trump–angry, amoral, and narcissistic–has a very different personality than Reagan’s, but he also meets most of the tests. With Trump, what came naturally to Reagan is an ideology of sorts; he believes that every human interaction has a winner and a loser, and the winner is the one who dominates the other. He uses his size, celebrity, dark sense of humor, and boundless self-regard to entertain his supporters and make them feel safe. In other words, his swagger is the method by which he gets rural Christians to provide unquestioning support for him even though he does not even remotely resemble them. That is the key to his success–the way he squares the circle of white Christian identity politics in the GOP.
The only test Trump fails is the athletic part. Riding a cart and playing golf is not the equivalent of riding a horse and working on a ranch. In that sense, Trump is a parody of Reagan and George W. Bush.