I have known many people and heard of countless more who live in foreign countries, do not have plans to live in the United States or the United Kingdom, and want to learn English. They do so because they have correctly discerned that speaking English gives them an advantage. It increases one's chances to obtain a well-paying job. It provides an advantage in business involving international trade or any international relations. Perhaps, more importantly, it makes viable the option to study at generally superior American universities. It seems that everyone in the world knows thatEnglish is the language of prosperity. That is, except Americans.
'Liberals' (the Americans most illiberal) don't want to require immigrants to learn English, which by itself sounds harmless enough. However, it no longer sounds harmless if we consider the de facto alternative is to spend millions of your dollars to create instructions, signs, voice prompts, and everything else under the sun in Spanish. In this manner, 'Liberals' do want to discourage immigrants from learning English.
I do not presume to know their motives, but in light of 'Liberal' policies across the board, we may reasonably conclude that, while 'Liberals' want immigration to be unchecked, presuming that such policy will result in more votes for the Democratic Party, 'Liberals' may also reasonably surmise that educated immigrants would be more prosperous and, therefore, more likely to instead vote for truly liberal (in the classical sense) policies, which are better represented by other parties.
Most fascinating to me, and perhaps most telling, these 'Liberals' are discouraging immigrants from learning the language of prosperity.