When I was a kid, the Chicano Movement was a huge deal in Los Angeles. For example, in 1970 the local band El Chicano's  instrumental Viva Tirado reached only #28 on the national Billboard chart, but it was #1 on KHJ-AM's Boss 30 Countdown  for three weeks. It was ideal for blasting from the speakers of your lowrider as you cruised Van Nuys Blvd.
The point of the word "Chicano," which first shows up in Google's nGram  around 1967 and peaked in 1976 before declining sharply, was that it referred to Mexican-Americans born in the U.S. The idea was to distinguish Mexican-Americans both from whites and from Mexicans, who often looked down upon Mexican-Americans as people who couldn't make it in Mexico. The Chicano Movement inspired a fair number of radical activists, such as Oscar Zeta Acosta , the original for Dr. Gonzo, Raoul Duke's "300-pound Samoan attorney" in Fear and Loathing in Las Vegas.
Whatever happened to Chicanos, anyway?
My guess is that despite the sizable outpouring of ethnic pride that the Chicano concept elicited from the Mexican-American masses, it didn't fit into elite plans for a broad Hispanic / Latino category, comprising both Mexicans and non-Mexicans and both immigrants and American citizens, whose vast numbers could be used to demand more Hispanic / Latino immigration, thus generating more jobs for Hispanic / Latino elites. "Chicano" was too particularist to be politically attractive to the top guys. Sen. Marco Rubio, for example, can plausibly present himself to Republicans as the voice of Hispanic opinion, but the Cuban could hardly present himself to even the clueless GOP as the authentic leader of the Chicanos.