Donald Trump was wrong to use Edwin Jackson's death to push his political agenda ... so says one of Jackson's closest friends, who says POTUS needs to focus on the REAL issue -- drunk driving.
We spoke with Minnesota Vikings LB Antwione Williams -- who was Jackson's college roommate at Georgia Southern. The two have been good friends for years.
Williams says it made him "sick" to see Trump using Jackson's death as a rallying cry for his immigration policy ... since the guy who allegedly killed Jackson was living in the U.S. illegally.
Instead, Williams says Trump needs to focus on the drunk driving problem in America -- since the suspect was allegedly nearly three times the legal limit when he struck and killed Jackson.
Williams also tells TMZ Sports about the kind of person Jackson was like off the field ... and shares his favorite memories from when they lived together.