Your I-130 petition for your son cannot be denied on this basis. But the fact that as petitioner, you received welfare may raise public charge concerns that your son, if given a green card may end up on welfare. You can overcome this charge if you can find someone to act as Co-Sponsor to join you in filing a Form I-864 Affidavit of Support.
Answered on Dec 27th, 2012 at 12:30 PM