ROME — The far-right extremist who wounded six African immigrants in a racially motivated shooting rampage in central Italy this weekend was a one-time candidate for municipal office who had kept a copy of Mein Kampf and Celtic crosses in his home. Photographs show he had a neo-Nazi tattoo on his face and, at the moment of his arrest, had an Italian flag draped over his shoulders as he performed a fascist salute.

But the gunman, Luca Traini, ran for election last year not with a post-fascist and nationalist party, but as a representative of the formerly secessionist Northern League. Under its leader Matteo Salvini, whom the gunman described as his “captain,” according to Italian press accounts, the party has rebranded itself, dropping the word Northern to attract voters in central and southern Italy who share Mr. Salvini’s anti-immigrant anger.

Ahead of Italian elections on March 4, there is plenty of it. Perhaps no issue has struck a greater chord with voters than immigration, and perhaps no Italian politician has voiced concerns about immigration more than Mr. Salvini.

In the aftermath of the shooting in Macerata, Mr. Salvini perfunctorily condemned the violence, which had followed the arrest of a local Nigerian immigrant accused of killing and dismembering a teenage girl. Mr. Salvini then argued that “unchecked immigration brings chaos, anger” and “drug dealing, thefts, rapes and violence.”