Why might some people oppose bilingual education while others advocate its use?

In the United States today, we have a fast growing, diverse population. A study shows that in three states bilingual education has been taken away in schools in those states. This same study shows that "the three states that passed anti-bilingual education initiatives enroll 43% of the English language learners in the United States." (http://sdkrashen.com/articles/tell_the_truth/all.html) When more than half of a schools enrollment does not speak English, bilingual classes SHOULD and MUST be offered in my opinion. In high schools, it is mandatory that you learn a second language and in most cases you must take at least three years of that language. So, if it is mandatory that English speaking students must learn a second language, why are some school systems making it impossible for students who do not speak English to learn a second language as well?
According to the article, there are two reasons why "we" or the states lost bilingual education; anti-immigrant attitudes and plain ignorance. Many people are ignorant to other cultures and do not understand their lives. At one time bilingual education was acceptable and positive in school environments, that unfortunately, decreased throughout the years. People have mixed feelings about immigrants however I truly believe that most of the people that are negative about bilingual education are depriving children of a better life because they do not like or appreciate these children's parents. School systems are trying to make a better life for the children and the many generations to come after. Being unacceptable to bilingual education also involves being racist. Our country is better than that and I truly believe eyes need to be opened and people should not be ignorant and stubborn. They should also understand that if this were their children they would be very hurt that they had their education being taken away from them.