A little commentary on the Butler situation:
https://link.medium.com/pDGTe5vxsXIn addition, the Intelligencer article states that Butler's organization does not describe itself as "Hindu," and Tulsi does. Tulsi became a Hindu as a teenager.
The history of Hinduism in the United States is complicated and the guru dynamic, as it was meant to be practiced, has been very difficult to achieve -- even relatively mainstream American "Hindu" organizations (the term is very much elective and self-applied) like ISKCON have suffered from abuse at the hands of unscrupulous gurus. While progress has been made in cleaning this up, the work is far from over and it will be a good while until Hinduism in America is purged of this kind of thing. Don't forget that "Hinduism" in the sense that we use that term today only definitively came to the United States in 1893, and to a large extent, wasn't even really established until 1965ish.
When that happened, Hinduism in the United States split in a few different directions, not all of them productive or, well, good. I am talking about the Americanized Hindu-derivative traditions, here -- again, the SIF is not a Hindu organization. It is an interfaith sect drawing inspiration from, among other things, Hindu thought. There are dozens of such societies in the United States and some of them are healthier than others -- Butler's is shady, and this is notable because it stands out as a negative example of Hindu-adjacent practice in the United States.
It is a good thing that we're having a discussion about Tulsi's faith; let's just ensure we're still operating in the context of, well, reality. Tulsi Gabbard is a Hindu who was initially raised in a Hindu-offshoot society -- this conversation has before drifted into calling her a "cult member" and writing off all Gaudiya Vaishanavas because some dude is running some shady organization claiming that lineage. This is especially relevant when you look at his website:
According to Veda and yoga, the perfection of life and of yoga is the achievement of pure bhakti (spiritual love). Yoga is not something one can join or quit, but is rather the eternal truth (sanatana dharma) of our identity. Yoga is an individual (rather than a team) pursuit or endeavor. While the association of like-minded seekers is encouraged, the concept of being “saved” by joining an institution or church is foreign (and alien to) the Vedic or yoga system.
American Hindu-adjacent groups often do this thing where they reduce important terminology into very general concepts, like calling bhakti just "spiritual love." Simply calling "eternal truth" the "sanatana dharma" is, similarly, of incomplete accuracy, and treating these terms so vaguely allows believers to read into them whatever they want, often by design.
Let's just be very careful about the scope of what we're talking about, here, because with this topic, there are many different classes of people going by similar names and using similar language doing very diverse things throughout.
EDIT: It's also worth noting that even ISKCON is still not held in very high regard by many Hindus. This entire topic has not yet been answered even among the community in a narrative or categorical sense, let alone with regard to Tulsi personally.