He hasn't changed much either. He has lucked out that a politically naive group of young people believes every single one of his decades old messages--verbal and otherwise-- and is giving him a huge boost.
The non-verbal and off-handed messages he gives are causing many of us to bristle, and he often delegates the dirty work of being a hard-boiled politician to others--still another form of messaging, but one that gives him plausible deniability. He seems like Chris Christie in that regard. Let's not forget he hitched his post to the NRA when he thought it would help him win once, and it worked.
The fact that the bulk of his supporters are so young helps his negative messaging of Hillary Clinton (because they grew up hearing it and do not remember her before millions got spent to demonize her), and helps him in that they don't know that his speeches have been pretty much identical for almost four decades, and that in spite of his rhetoric he has been living very well under capitalism and has never known anything different except for when he went to visit the "socialist" dictator Daniel Ortega, Fidel Castro (who rebuffed him) and a honeymoon trip to Russia. He doesn't know any more about really living as a "social democrat" than any of the rest of us do, except in his reading material and in his imagination. He is now in his mid-seventies--has lived his whole life in the U.S. after being born in Brooklyn.
Another point to make: while the gay rights movement has received national attention and has been embraced widely, the women's rights movement seems to have lost the populism it once had. It is as though those powerful, political and economic mechanisms that were put in place to help raise awareness and to fight for marriage equality packed up shop and left the women's movement, and the fight against racism (huge movements that happened together during the turbulent '60s) to fend for themselves. Meanwhile, the right-wing is systematically rolling back hard won voting rights, and needed resources for minorities; and access to needed resources and health care for women (and of course the children and families that depend on them). Women's rights cut across the socioeconomic spectrum and blend right into other civil rights battles. Women come in every size, shape, income bracket, religion, and skin color.
Thank goodness for women who fight to help others. Thank goodness for Hillary Clinton.