The gap between rich and poor is widening in almost every state, a private research group said in a report that also found the Great Plains and mountain West lagging other parts of the nation in general economic climate. Northeastern states earned top grades in the annual 50-state economic report card compiled by the Corporation for Enterprise Development, a research and consulting organization whose study was financed by corporations, labor unions and private foundations. A growing disparity between rich people and poor people was evident throughout the country, with the income gap widening in all states except North Dakota, Hawaii and Alaska, the study found. It evaluated state economies on more than 125 variables and graded states from A to F in four areas: economic performance, business vitality, resource capacity and development policy. California, Connecticut, Maryland, Massachusetts, New Jersey, Vermont and Virginia were the seven states that got all A’s and B’s.