More than a quarter of American children--and half of black children--belong to families too poor to fully qualify for the ＄1,000-a-year child tax credit, which President Bush signed four years ago and has cited in arguing that his program of sweeping tax cuts helps low-income families, a new study has found. With an annual value of $47 billion, the credit is the government's largest children's subsidy and one that has provoked sharp partisan fights. Many conservatives, viewing it solely as a tax cut, want to reserve the credit for families that owe federal income tax. Many liberals, vie-wing it as a broader children's allowance, want to extend it to poorer workers, who they say need it most. Still, the study found that the families of 19.5 million children were too poor to receive the full ＄1,000 benefit. About half get a partial benefit, and half get nothing. Newt Gingrich, the former Republican House speaker, expressed surprise at the racial gap. 'That's a stunning number,' he said, referring to the half of black children who fail to receive the full credit. 'I'd find a way to make sure those kids get the money as part of a broader post-Hurricane Katrina plan.' Framed as middle-class tax relief, the credit passed in 1997 and offered ＄500 per child to families that owed income tax. It was doubled in 2001 and made partly available to families too poor to have income tax bills. Len Burman, a co-director of the tax center and the study's author, said it might actually exaggerate the amount going to the poor since it assumed all eligible families received the credit. In practice, studies suggest that poor and minority families claim tax credits at lower rates. Told of the study, which will be published Monday, some conservatives repeated their opposition to making the credit more of an antipoverty program. Mr. Mitchell said that low-wage workers received a total of ＄39 billion a year from a similar program, the earned income tax credit. 'It's not like they're not getting any redistribution from the government,' he said. 'We want less income redistribution, not more.' Both sides in child tax credit debate have cast their arguments in moral terms. 'The income gap is wide and growing,' Ms. Snowe said. 'We're talking about giving a helping hand to families who through no fault of their own are at or near poverty.' Mr. Mitchell of the Heritage Foundation said income redistribution was morally problematic, since it punished people for economic success. He also called it economically inefficient, arguing that it discouraged work among both rich and poor. What can we learn from the first paragraph?