Most people are stupid, in that they don't think for themselves, they don't utilize critical thinking, and this, m'dear, leads to the varied and continuous maladies/tragedies that befall us human beings, past, present and surely in the future to come, sadly.
Now, if you accept the above generalization, there are three types of folks who will "sway" either implicitly or explicitly the masses, one type being the selfish, power hungry, sociopaths, who believe human beings are pawns, they gain, you lose, me, me, me, me, me types.
And then there will be your altruists, who see humanity as a whole, who think when the individual suffers the community suffers, when the community is healthy the individual will be healthy.
And then there's your third type, the reclusive intellectual, they might be writers, poets, painters, scientists, but they create works of art and, or workable systems/theories that eventually benefit mankind tremendously.
^There's more, I'm sure, but those are the three that come to mind.