Here is the paradox of the idea of romantic originality: to be original is to be off-center, eccentric. Yet canonical authors are also supposed to be representative (of something more than themselves) and normative in some cultural sense. Bob Perelman went into this a bit in The Trouble with Genius, for the modernist period, but the problem is there beginning with William Blake. You can tell that Blake was, well, just a really weird guy. His prophetic poetry is interesting, but heterodox religiously and unlikely to be influential in its own time. He is an anomaly, not the typical 18th century poet.
So now we have poets that are one-of-a-kind, romantic geniuses. Even Pound, no romantic, fits the paradigm, because his attempt to set normative rules for culture tend to go off on bizarre side-errands. Yeats is weird like Blake was. Eliot tried to steer a more orthodox course. Even Milton was too free-wheeling and protestant for him. So Eliot was able to found a school of poetic criticism that was normative rather than eccentric. He was no visionary like Yeats. Harold Bloom rebelled against this New Criticism in order to champion Blake and the weirdness of the romantic sublime, but his criticism ended up being normative with The Western Canon and Shakespeare the Invention of the Human.
I am not making value judgments about what I like, or what I think is weird. I am talking about how it looks to society in general. Romanticism and literary modernism always want to seem original (eccentric) but also normative culturally. What I mean by normative culturally is what is taught in school, or what you need to know to be an educated person with some cultural capital. The values of School always conflict with the anti-academic values of modernism itself, its irrationality and interest in the occult.
The occult becomes mainstream with Ginsberg. More than Bloom, he made Blake and surrealism a kind of semi-popular art. The whole 1960s was like something that Allen Ginsberg and his friends invented a little earlier. All the occult and astrology stuff that Duncan loved.
So that is where Lorca comes in to American culture. He is valued because he is exotic and the model of the romantic genius. He cannot be processed as a "normal" poet, one who simply writes good poems. But founding a poetics on him, like Bly tried to do, doesn't work either. You need an eccentric view, like that of Spicer, to be able to process his work.
Romanticism sacralizes the poetic imagination in two directions: one faces backward, with an interest in tradition, lore, organic society, nature. One faces forward, with emphasis on originality, novelty. There is a fundamental tension here. You can't be original by going back to the origins: you must also be distinctively original and modern. What you get are really bizarre, eccentric recombinations of ancient lore or religious symbols. Gadamer is very good on this when he examines the romantic response to the enlightenment.