The ad in question depicts citizens of varying ethnicity while "America the Beautiful" is sung in alternating languages, with English being the bookend languages. The theme is clearly intended to be unity in spite of diversity, carried by an iconic melody that remains recognizable and loses none of its meaning regardless of what language it has been translated into.
"If you don't like it, if you're offended by it, then you're a racist," Beck insisted of the ad. "That's all this is, is to divide people."
Once again, the ad depicted a a multicultural yet unified America. Ergo, what Beck is insinuating is that it's divisional to confirm that bilingual minorities in the United States actually exist.
Reminiscent of the way he tried to insist that empathy, one of the most positive words in the English language, ties directly into fascism and genocide, Beck has responded to an ad with a core theme of unity by declaring it a deliberate effort to divide the nation.
For the record: Yes, Mr. Beck, if you can get this offended by a mere confirmation of the existence of minorities in America, that makes you racist to the core.