my 2cents:
write only to your own senators and your congressman/woman, but do follow up closely once you got reply from them. Talk to the one who actually worked on your case, and let him/her to follow with FBI (if NC). If he/she simply works with USCIS, you are just wasting your postage (and your big efforts too). So tell them requesting USCIS is useless, tell them do not bother about USCIS.
write only to your own senators and your congressman/woman, but do follow up closely once you got reply from them. Talk to the one who actually worked on your case, and let him/her to follow with FBI (if NC). If he/she simply works with USCIS, you are just wasting your postage (and your big efforts too). So tell them requesting USCIS is useless, tell them do not bother about USCIS.