The Department of Justice is investigating the nonprofit of billionaire Reid Hoffman, which made contributions that were partially used for E. Jean Carroll's legal expenses during her civil lawsuit against President Trump , a source familiar tells Axios. Why it matters: The investigation raises concerns about a pattern of retaliation against Trump critics while testing the independence of DOJ officials. Hoffman, a LinkedIn co-founder, has donated millions to Democratic causes and the party over the years and is a longtime Trump critic. The president previously alleged Hoffman is a funder of "radical left" groups that promote political violence. What they're saying: "The investigation is more focused on Reid Hoffman's nonprofit," American Future Republic, than Carroll herself, a source familiar with the DOJ's operations tells Axios. "It's related to E. Jean Carroll and her deposition, but she is not the subject of the investigation." "The investigation is ongoing...…