Are Mexican Americans a race or an ethnicity?

Sheryl Luna reviews "In Manifest Destinies: The Making of the Mexican American Race," (NYU Press 2007) by law professor Dr. Laura E. Gómez on Latina Lista.

Sounds interesting: "The book is a close historical account of institutions, colonization and violence that was, in her view, propagated based on views of Mexican-Americans as an inferior race. She supports this argument with clear researched documents that indicate American acquisition of the area was anything but peaceful."