Eight days after a gunman with an AR-15 rifle killed 17 people at a high school in Parkland, Fla., a major bank cut ties with the National Rifle Association.

The bank, the First National Bank of Omaha, was among the first businesses of at least a dozen to scrap special rates or discounts to the five million people the N.R.A. says it has as members.

Supporters and detractors of the N.R.A. have butted heads over the issue on social media, calling on partner companies to either stay put or step away, essentially leaving them with no neutral ground.

Of those companies that did cut ties, many said they did it in response to consumer complaints.

In a statement on Feb. 24, the N.R.A. said the companies, “in a shameful display of political and civic cowardice,” were trying to punish its law-abiding members who had nothing to do with the Parkland shooting.