How is Shambhala Buddhism as founded by Chögyam Trungpa Rinpoche and continued by folks like Pema Chodron different from traditional Tantric Buddhism such as that practiced by the Dalai Lama? Does Shambhala rely on the same texts as Tibetan Buddhism?
In the editor's preface of my copy of Trungpa's 'Shambhala - The Sacred Path of the Warrior' it is claimed (and I do well agree with that), that the Shambhala teaching is "a major departure" from Trungpa's earlier, popular but quite orthodox Tibetan Buddhist books. This is further elaborated, saying that the outlook is rather secular than religious and in the broadest possible way universally-human.
This fits quite well with my personal impression of the teaching, that it tries to avoid anything too specifically buddhist, too 'sectarian', too foreign (for westerners), too 'exotic', but rather attempts to - if I may say so - lead westerners (that unmistakably are the audience talked to) back to a common human source of dignity rather than providing yet another foreign source of 'spirituality' to draw from.
This also means, that it does not rely on any scriptural source, rather - in a rather unimportant and personal way - it relies on the tradition of the Shambhala kingdom.
Original Shambhala as founded by Chogyam Trungpa was not supposed to be Buddhism at all, it was supposed to be a secular teaching loosely based on Buddhist principles intended to heal society from its insanities, toward Enlightened society.
"Shambhalian practices focus on using mindfulness/awareness meditation as a means of connecting with one's basic sanity and using that insight as inspiration for one's encounter with the world." (Wikipedia)
"Shambhala Buddhism" is an unfortunate (IMHO) attempt of Trungpa's son to bring Shambhala back into familiar territory.
Personally (and I belong to a Shambhala sangha and have 20+ years as a Zen Buddhist practitioner), it's good to see Shambhala returning to it's roots. The "old" Shambhala incorporated too much of Trungpa's crazy wisdom, a scheme that finally killed him through alcohol poisoning. I'm always shocked when people from other Shambhala centers across the country visit our place and admit that they have very little meditation discipline. Instead, Shambhala focuses on training courses, most of which cost money.
It's much more helpful if people get their meditation discipline down FIRST, then try different things. The Buddha knew what he was talking about. Sitting meditation, and mindfulness practice when we leave the cushion, are the heart of this practice, and they work! Thankfully, those disciplines are offered at Shambhala, and the Sunday sits are very Zen like with 20 minutes of sitting meditation, 10 minutes of walking meditation, and this goes on from 9Am to around 11AM. After that a "teacher" gives a talk of sorts (not a dharma talk). I usually skip this, and go help w/ food preparation for the free community Sunday lunch at noon. Or go for a walk.
Shambhala is one expression of buddhism with the Kalachakra at it's roots. It addresses hineyana and mahayana teachings as most things are taught in buddhism - symbolically. It pulls from Kagyu and Dzogchen traditions, where the Dalai Lama is from the Gelug tradition. Trungpa Rinpoche worked closely with Suzuki Roshi and was in spiritual agreement with Gerald Red Elk, the Lakota Sioux shaman. His son, Sakyong Mipham Rinpoche, is teacher to Taoist lineage holder Eva Wong. This speaks to the universality of true and direct spiritual 'attainment'. The teachings themselves are historic - read The Epic of Gesar - yet are considered new and "terma" because the direct experience of a master must be taught to an entirely new culture. No monks or nuns in "the west." Look at Tibetan iconography and it won't make much sense, but those raised in such a culture see it filled with meaning. Westerners just automatically think "cult." In Eastern culture, especially Japanese (my Ikebana teacher shared this, as well as stories from Eva Wong's empowered qigong teachers), one NEVER questions a teacher. In the West, we question everything!
In a nutshell: Shambhala is an expression of buddhism; Theravada is an expression of buddhism; Galupa is an expression of buddhism; Zen is an expression of buddhism; Chan is an expression of buddhism; etc.
And - buddhism is not a religion but a philosophy and a meditative path of direct experience, not study.
Hope that helps a super complicated question!