Why do so many people think they'll have to learn Spanish with the growth of the Hispanic population?

Many people think that since it's said Hispanics will about 30% of the U.S. population by 2050, they will have to learn Spanish? The Hispanics who speak only Spanish are the recent immigrants. Their children speak english and they prefer to speak english over spanish, so why would Spanish be necessary?

How Hard Is It To Learn Spanish On My Own?

I will not learn Spanish in school because I already chose another language. But I still want to learn Spanish because of the huge Spanish-speaking population in the USA.

So, is it easy or difficult to learn Spanish on my own either through traveling to Spanish-speaking countries or computer software?

I don't speak Spanish, how do I handle that in a job interview?

I have a job interview this week at a retail store. I live in a city with a high population of Spanish speakers with many who only speak Spanish. I have worked retail here before and it was definitely a hindrance. That employer never asked if i spoke Spanish however, assuming I did since I'm Hispanic.

I'm concerned this employer will ask however. If they do ask, how can I respond in a way that makes it seem like less of a handicap?

How do I say “Speak English, or don’t speak to me.” in Spanish?

I live near Miami, and the majority of the population either speaks spanish, is rude, or speaks rude spanish lol. I just want to be able to say this to them to get my point accross! (they came here from 'wherever' because it's better, but refuse to learn the language?!?!?!)
Go read this, you'll see why it p*isses me off.

http://blog.myspace.com/index.cfm?fuseaction=blog.view&friendID=24475272&blogID=246980610&Mytoken=77F48680-7CB7-4114-BD28609AA88158306325874

And "bella" and "come break me down", you're both idiots. There are Immigration laws for a Reason.
Mr.Inquisitor.

You're one of the people I'm upset with. Yes, I realize I'm in miami and that I'm the minority here, but you fail to get it through your obviously brick-thick skull that Miami is a part of the UNITED STATES, in which ENGLISH is the national language. Would you move to Germany and expect it's residents to cater to your language deficiency? I think not.

I'd really love for you to read my blog (link above). And feel free to spout some more horse-s*hit at it. I won't even waste my time deleting it. I'd like eveyrone who reads it to see the fault in your reasoning.