A persuasive or argumentative essay must include very specific things in order to be considered successful.
First, an essayist must consider (or find) evidence which supports the stand. In the case of requiring immigrants to learn English of they are to live in the United State, one must find academic and reliable sources which back up the essayist's stand.
Second, an essayist must consider his or her audience. If an audience is supportive, the essayist can depend upon pathos (emotional appeals). A supportive audience does not need to be persuaded, and an emotional appeal only solidifies the support of the audience.
Another type of audience is a hostile audience. A hostile audience vehemently disagrees with an essayist's point of view and stand. In order to sway a hostile audience, if possible at all, an essayist must use both ethos (credibility) and logos (reason). A hostile audience will not be swayed by emotional pleas.
The final type of audience is the wavering, or undecided, audience. An essayist must use pathos (limited), ethos, and logos in order to sway the wavering audience.
Finally, an essayist must consider the approach used in the presentation of information. Most all persuasive essays are written using an emphatic approach. With an emphatic approach, the essayist saves the most impressive information for last.
I have attached a film clip from PBS discussing the issue of immigrants and the English language.