Hispanics are growing more divided about how they view illegal immigration, and native-born Hispanics aren’t as convinced of the contributions of illegal immigrants as they used to be, according to a study released Thursday.

Hispanics are split when asked to assess the effect of illegal immigration on Hispanics living in the United States: 29% say it has had a positive impact, 31% negative and 30% believe it made no difference, according to the study by the non-partisan Pew Hispanic Center. That is a sharp decline from a 2007 survey, when 50% of Hispanics said illegal immigrants were having a positive impact.