Th US has huge coal reserves, but choosing to use coal instead of oil requires careful consideration of the environmental consequences.
Coal does not burn as cleanly as oil. Burning Coal may leave solid residue (ashes) which are a hazardous waste. Both these problems can be solved by technology and at a increased monetary cost.
Less easily solved are the environmental damage caused by mining operations. Both open pit and underground mining have devastating effects on an area.
More use of electricity will work only if vastly increased generation capacity is available. The choises are oil (and natural gas), coal, hydro-electric, wind, solar, nuclear.
Use of oil to generate electricty of course will not save our oil resources. It would actually use more due to the loses in power transmission from the central plant to the user.
Transmission loses are dependent an the distance of the sourse from the user, but of course, not dependent on the method of power generation.
Coal: see above
Most good locations for hydroelectric dams in the US are already being used, and there is strong pressure from the Environmental Movement to not allow any more dams and to remove many existing dams.
Wind generation has so far not proven to be reliable enough and there are only a limited number of places where it is really feasible… Improved technology will improve the situation someday, but it is still unlikely wind power would be able to supply any significant percentage of even our current need in the foreseeable future if ever.
Solar generation requires expensive somewhat rare elements, is not with current techcnology: reliable enough. It works in the daytime only and in a limited number of areas. The evironmental damage caused by shading large areas with solar collectors must be considered.
Nuclear is probably the least expensive, cleanest , and safest method of power generation currently availab