How much does being a low-income minority add to my chances?

To make things short, I was rather disappointed with my recent SAT score (1390), since I understand that it greatly lowers my chances of getting admitted to the colleges on my list. My family is very poor, so I am forced to apply to those top colleges that meet 100% need for admitted students. Now, I have also heard that certain minorities and students from particularly low-income backgrounds get a leg up in admissions. Since we are certainly in the low-income bracket, and since I am technically Hispanic, I was wondering how much these facts would add to my application. Would a top college be willing to overlook the 1390 in light of my status? I am a good student in school otherwise (4.2 GPA, top of the class ranking, etc.) Hopefully, the upcoming ACT will go a bit more smoothly.

Being low income might increase your chances slightly at these schools if and when they attempt to reflect a cross-section of the population.

The super-selective colleges prefer to be opaque about their admissions criteria, so you cannot really know how that may affect your application.