More information is available in this article. The information comes from a Pew Hispanic Center report released recently.
The actual rate is highest among blacks at 39.1 per cent in 2010. 35 % of Latino children lived in povety and 12.4 per cent of white children.
Poverty has been increasing in the U.S. since the 2007-09 depression especially among Latino children. The U.S. Census Bureau released a report in mid-September that found "46.2 million people in poverty in 2010, up from 43.6 million in 2009 ─ the fourth consecutive annual increase and the largest number in the 52 years for which poverty estimates have been published."
Latinos now comprise the largest share of poor children.The Pew Hispanic report notes "In 2010, 37.3% of poor children were Latino, 30.5% were white and 26.6% were black." In spite of the lower percentage of poverty among white children the absolute number is quite large and hence larger percentage wise than even blacks who have the highest percentage of children in poverty. For much more see the link above.