The dividers are this nation's financial elite who bankrolled the founding of the Tea Party to carry out their political desires. It is they who radicalised politics - but the Tea Party is known for its conservative views. Conservatives, by definition, cannot be political radicals.
No, I'll tell you who radicalised politics: the kind of people who think the issue of transgender toilets is one of the biggest issues we face, the kinda people who think labelling everybody and pigeonholing everybody is a fantastic idea, the kinda people who think the question "what best describes your sexuality?" is a great question for job application forms.
These asswipes are the dividers in politics today. Their dividing of people provides the environment for tensions to flourish - between black and white, between gay and straight, etc.