The American Research Group poll released Tuesday indicated Obama of Illinois was preferred over Sen. Hillary Clinton, D-N.Y., 55 percent to 37 percent among Maryland Democrats and 56 percent to 38 percent among Virginia Democrats.

The two states and the District of Columbia conducted their primary elections Tuesday.

Among Republicans who said they were likely to vote in their primaries, McCain of Arizona outpaced former Arkansas Gov. Mike Huckabee 50 percent to 25 percent in Maryland,and 54 percent to 32 percent in Virginia, the poll indicated.

For each party poll in each state American Research Group, based in Manchester, N.H., interviewed by telephone 600 people Friday and Saturday. All polls have margin of error of 4 percentage points.