How close are far right and far left political movements to cults?

I am currently reading a book called Captive Hearts, Captive Minds: Freedom and Recovery from Cults and Other Abusive Relationships written by Madeleine Landau Tobias and Janja Lalich. As I learn more about how cults function, about the thought control techniques they employ to recruit new members and convert them to unthinking automatons capable only of mouthing cult talking points and thinking the cult leader’s thoughts; I have been struck by how similar the results of cult indoctrination and the extremes of political totalism are.

Wikipedia has a nice article defining cults and identifying what makes an organization a cult.
What political movements today border on being cults? What cultic features do they incorporate, and in what ways do they differ from a true political cult?