Exit polls showed the referendum headed for an easy win, with support from most segments of the population, The Baltimore Sun reported.

Religious groups, including the Maryland Catholic Conference and many black churches and ministers, opposed slot machines. But their stand appeared to have little effect on their members.

The Rev. Frank O'Connor, 84, a Catholic priest, told the Sun that slot machines appeared to be "a decent way to raise more for state expenses." He said his vote was a reluctant one because he understands the danger of gambling addiction.

Gov. Martin O'Malley strongly backed slot machines. He said the additional revenue, estimated at $600 million, will help Maryland weather the economic slump.