Reconstructionism has always been part of neopaganism to one degree or another, but its increased prominence in recent years has largely been a reaction against the eclecticism of Wicca, and to a lesser extent against its politics. Wiccans tend to combine all goddesses together as aspects of a single Goddess, and all gods as aspects of a single God.
While this is theologically defensible (and was done to some extent in ancient times, as witnessed by the long prayer to all the goddesses of the world as aspects of Isis near the end of Lucius Apuleius' “Golden Ass”) it is not very accurate to the way most ancient pagans saw their deities or their religion.
The idea of a single, universal Goddess is present in Hinduism, where the myriad deities are manifestations of the basic masculine and feminine divine powers under different forms. Even in Hinduism, though, the different local goddesses receive much more attention than the universal Goddess. The basic problem here is that most pagan religions are genuinely polytheist, but Wicca as it is usually practiced is duotheistic, with the result that real and significant differences between deities and cultures are “flattened out” in a homogenous list of deity names devoid of context.
Reconstructionism attempts to get away from the eclecticism of Wiccan theology by reconstructing specific pagan religions from the ancient world, such as Hellenismos (one term for the ancient Greek religion) or Druidactos (one of many proposed names for the ancient Celtic religion). Unfortunately, there are significant problems facing Reconstructionist religions of all kinds, a few of which I will address in my next blog.