The 2018 Farm Bill legalized all hemp production and everything in the composition of hemp other than Delta-9 THC, of which hemp must contain below 0.3%. This is the standard for hemp on the federal level, so CBD, CBC, and every other cannabinoid other than Delta-9 THC, including Delta-8 THC, are legal. Under state jurisdiction, the legality varies.
Consumer appeal for Delta-8 THC relies on the fact that this novel cannabinoid, like Delta-9 THC, is psychoactive. However, reported use claims that the effects of using Delta-8 THC are markedly different than Delta-9 THC. Although this is interesting to note, the demand for the cannabinoid has yet to be made clear. Additionally, other novel cannabinoids, such as CBG, have found biomass value drop 82% over the last year. While interest in these substances peak at introduction, allowing them higher prices than traditional THC and CBD products, the inflated price of Delta-8 THC products will likely follow the pattern set by previous novel cannabinoids.
Additionally, the DEA may be coming after Delta-8 THC. On August 20th, they released the "Implementation of the Agricultural Improvement Act of 2018", which would make the production of Delta-8 THC illegal. While natural Delta-8 THC is present in hemp and cannabis, it is not present in extractable levels worth using. Instead, most Delta-8 THC on the market is synthesized from CBD, and the federally legal Delta-8 THC is mostly synthesized from CBD derived from hemp. While this is currently legal in a gray area, the proposed regulations would label all synthetically derived tetrahydrocannabinols as schedule 1 controlled substances.