Of old, the demagogue was also a general, and then democracies changed into tyrannies. Most of the ancient tyrants were originally demagogues. They are not so now, but they were then; and the reason is that they were generals and not orators, for oratory had not yet come into fashion.
Most writers, I'm afraid, live very boring lives sitting in front of a screen. However, having said that: every writer puts a bit of themselves into the characters to bring them alive.