Most of the dead were because they didn't agree with those in power.
Yes, but they were also dead because others, devoid of moral fiber or intestinal fortitude, went along with those in power.
We have the ingredients today, here, if the people are disarmed.
We have a large segment of the population which has become superficial, oriented only toward that which feels good and entertains them or fills their bellies. We have a media devoid of principle, with little dissent, echoing and promoting the ideas of a (at least to many) charismatic Socialist, who has promised them things he cannot deliver.
The media will direct the anger produced by that toward their idealogical enemies, and, devoid of moral fiber to restrain the masses, the only limiting factor is the ability of the targeted people to provide armed resistance.
If the Second Amendment is overrun, it will get very nasty out.