The rebranding of Buddhism in the English speaking world began in Britain in the 1830s. It was helped along by the publication of Darwin's On the Origin of Species in 1859. Edwin Arnold's best selling humanist retelling of the Buddha's life, The Light of Asia, was published in 1879.  It's no coincidence that bodhi (literally 'understanding, awakening') is translated as Enlightenment (upper-case E), since the Victorian translators of Buddhism were the intellectual descendants of the European Enlightenment and wanted to explicitly align the two movements. Of course we also have a fair number of Romantics who were appalled at the idea of explaining everything (or anything), and took flight into the realms of the sentiment and imagination where science could not, and would not, then follow. (It can now, but that is another story!)
One consequence of this has been a certain amount of confusion when confronted by traditional Buddhism which appears to be a lot more superstitious and, frankly, theistic than one has been lead to believe it ought to be. Some of us Westerners have been prompted to wonder out loud, with no apparent irony, how traditional Buddhists could be getting Buddhism so wrong. There has been a tendency to see any cultural form which is less than austerely rational as a 'corruption' of the original supremely rational Buddhism. For some reason Theravāda scholastic orthodoxy became the poster child for this rationality, despite a pre-scientific worldview, and well into the 20th century the entire edifice of Mahāyāna and Tantric Buddhism was seen as a 'later corruption'. The irony is that while we are contemptuous of Asians who have allowed Buddhism to change to meet their changing needs, we are engaged in exactly the same project.
This attitude is a complex stew including ingredients such as Imperialist and Colonialist superiority delusions (aka orientalism; or racism); generalisations from the Protestant critiques of the Roman Catholic Church (and in particular Protestant historical narratives based on the rise, corruption and fall of the Roman Empire); and the fear that with the death of God (pronounced by Nietzsche in 1882) that everything would be permitted, and morality would collapse. Most of these Victorian themes are still unresolved and active, often unconsciously, in British public discourse about religion. Again, there is also an important and influential Romantic trend in Western Buddhism which positively glories in the irrational and superstition, but I won't deal with that now.
A passage from the Vinaya (Vin ii.139) shows that this confrontation with superstition is not a new concern for Buddhists. However the Vinaya seems to have allowed quite a lot of latitude to bhikkhus when dealing with ordinary people. The passage involves "the group of six bhikkhus", a gang of miscreants whose (mis)behaviour leads to many new rules being laid down. At the time they were apparently learning and teaching metaphysics (lokāyata) and worldly knowledge (tiracchānavijjā). The PED suggests that lokāyata means: "what pertains to the ordinary view (of the world), common or popular philosophy", or as Rhys Davids puts it elsewhere: "name of a branch of Brahman learning, probably nature-lore'; later worked into a quasi system of casuistry, sophistry."  The word also occurs in Sanskrit and Monier-Williams defines it as 'materialism'. Tiracchānavijjā is literally 'animal knowledge', a tiracchāna is something which 'goes horizontally' i.e. an animal; but the dictionary suggests that tiracchānavijjā means "a low art, a pseudo-science". I take the general drift of the passage to be saying that the 'group of six' monks had become interested in the popular beliefs and practices of the local people, or perhaps had not abandoned their ancestral religion.
The important event in this text comes when the Buddha sneezes while delivering a discourse, and is then loudly interrupted by a number of monks calling out:
jīvatu, bhante, bhagavā; jīvatu sugatoThis - jīvatu: the verb √jīv 'to live' in the third person imperative - is the Pāli equivalent of saying bless you or gesundheit (= good health). The Buddha asks the bhikkhus: "When 'life' (jīva) is said to one who has sneezed, is that a this reason he might live or die?" They answer "no". He then forbids the monks from saying jīvatu. However this causes the bhikkhus problems because the householders continue saying jīvatu when the bhikkhus sneeze, and are angry when the bhikkhus do not respond in the traditional way. So the Buddha tells them:
May the Bhagavan live, Sir; may the Sugata live!
Gihī, bhikkhave, maṅgalikā. Anujānāmi, bhikkhave, gihīnaṃ ‘jīvatha bhante’ti vuccamānena ‘ciraṃ jīvā’ti vattu’ntiHere the Pāli word maṅgalika means 'superstitious, looking out for lucky signs', from maṅgala 'lucky, auspicious, prosperous' (c.f. the word omen). The text seems to suggest that lokāyata and tiracchānavijja are synonymous with maṅgalika. Also in this vein is a short sutta in the Aṅguttara-nikāya where the Buddha makes a distinction between householders generally, and lay disciples (upasaka/uapsikā), saying that an exemplary lay disciple "is not eager for protective charms & ceremonies".  We see here the concern, visible throughout the Vinaya, to keep the behaviour of the bhikkhus distinct from householders (gihī).
Monks, householders are superstitious. When a householder says 'live Sir' (jivatha bhante) to you, I allow you to respond with 'long life' (ciraṃ jīvā). 
This superstitious attitude also seems to be addressed by the Buddha in the Mahāmaṅgala Sutta, a very well known text from the Sutta-nipāta collection. Although this sutta is spoken to a deva, it includes supporting one's parents, cherishing one's wife and children, and having a peaceful occupation as examples of mahāmaṅgalaṃ (literally 'big luck') 'the highest blessings' or perhaps 'highest performance, great happiness or blessing' (following Saddhatissa's translation notes). Clearly the concerns of the text are those of householders. In the light of Vinaya reading above, we might see the Mahāmaṅgala Sutta as saying these things are 'good luck' rather than 'highest blessing', i.e as a re-contextualisation of the idea of what constitutes luck.
I think this demonstrates one way that the Buddha, or at least the early Buddhists, handled superstition. Direct opposition was unlikely to be very effective, since it was deeply embedded in the culture. For those of us who commit ourselves to Buddhism, it is vital that we examine our beliefs; the conditioning that we have received from family, peers and society, and begin to unravel it in order to free our minds from those limitations. But there's not much mileage in demanding this from people who do not share our commitment. We could rail against superstition, and where we see it as definitely harmful we probably should speak out against it, but on the whole the main thing for Buddhists is dealing with our own belief structures. Buddhism is something we take on for ourselves - e.g. upasampadā the word often translated as 'higher ordination' really just means 'undertaken, taken on'.
Sometimes it's more important to be polite than to be right.
- On this subject see: Almond, Philip C. (1988) The British Discovery of Buddhism. Cambridge University Press.
- Dialogues of the Buddha, p.166f. Online: www.sacred-texts.com
- Vin ii.139. ('Live long and prosper' would be ciraṃ jivatu vaḍḍhatu ca)
- AN 5.175. See also Thanissaro Access to Insight.
Since writing this I discovered the following in The Making of Buddhist Modernism by David L. McMahan:
"Buddhist studies pioneer Thomas W. Rhys Davids (1834-1922) first translated bodhi as "Enlightenment" and explicitly compared the Buddha with the philosophers of the European Enlightenment" (1882. Lectures of the Origin and Growth of Religion as Illustrated by some Points in the History of Buddhism. Hibbert Lectures. New York: Putnam. p.30)