If I really wanted to divide Americans and to capitalize on every difference we have, I would constantly identify everything that makes us different and focus intently on those differences. I would say, "We need to continue to have a CONSTANT conversation about race, sexual orientation, income inequality, etc". I would say that one group is at war with another group. "White supremacists are everywhere. There's a war on women. The 1% are profiting off the backs of the poor." Etc, etc.
OTOH, if I wanted to unite people, I would focus on what we all have in common. The shared belief in our system of laws and governance, in American ingenuity, in freedom over tyranny, in tolerance, etc. Even if I saw racism, I would double-down and remind everyone where we came from and how much progress we've made on race.
Does constantly pointing out our differences (skin color, education, gender, sexual orientation, income, etc) unite us in your opinion?