THAT the Reagan administration may indeed be something new on the American scene is suggested by the fact that no less than two major programs assessing its domestic social policy were launched shortly after it came into office. One is the Urban Institute’s “Changing Domestic Priorities Project,” the other the program being conducted by Princeton’s Urban and Regional Research Center. And, of course, we also have the ongoing analyses of federal budgets in the Brookings Institution’s annual Setting National Priorities volumes.