Twitter racists freak out after Mexican-American teen sings national anthem at #DemDebate

The return of 15-year-old Sebastien de la Cruz -- aka El Charro de Oro -- to national television on Wednesday brought with it another round of criticism from Twitter users apparently stunned to discover the existence of Mexican-Americans.

De la Cruz sang the national anthem prior to the debate between Democratic Party presidential candidates Hillary Clinton and Sen. Bernie Sanders (I-VT). Some of the worst reactions can be seen below:

As CNN reported at the time, de la Cruz was hit with similar invective in 2013, when he sang the anthem -- in full Charro regalia -- before the third game of the NBA Finals, with some describing the San Antonio native as an "illegal alien."

"For those that said something bad about me, I understand it's your opinion," he said at the time. "I'm a proud American and live in a free country. It's not hurting me. It's just your opinion."