As an amendment to a Homeland Security Bill in 2008, Arizona Senate Bill 1108, the "Anti-Ethnic Studies" bill, sought to establish that "a primary purpose of public education is to inculcate values of American citizenship" by proposing to eliminate the state's ethnic-studies programs and ethnic-based organizations characterized as "un-American." We investigated undergraduate student responses to the proposed amendment to the SB 1108 bill and associations with civic engagement, stress, ethnic identity, and mental well-being (depressive symptoms and self-esteem). Ninety-nine undergraduate students who self-identified as Mexican, Mexican American, or Chicana/o completed an online survey. Their responses indicated that more stress due to SB 1108 was significantly associated with more discrimination stress, lower self-esteem, and more depressive symptoms. We found that students that were more civically engaged in general were more engaged with SB 1108. Students with less positive or examined ethnic identity were more likely to be disengaged with SB 1108. Moreover, even if students felt high levels of stress from SB 1108, their engaged responses buffered them from the potentially negative effect of this proposed measure on self-esteem. In contrast, those who felt stress but were not engaged had significantly lower self-esteem. These findings have important implications for understanding the effect of nativist policy on Chicana/o youth and validate the benefits of civic engagement for the well-being of ethnic minority students. [ABSTRACT FROM AUTHOR]