Despite all the lethal mayhem caused by the Stand Your Ground laws now on the books in nearly two dozen states, the gun lobby is inviting more trouble.

In Georgia, for instance, a pernicious bill approved by the House authorizes an array of dangerous laissez-faire gun provisions. One would allow convicted felons who kill someone with an illegally possessed gun to seek justification under the state’s Stand Your Ground law. A second would allow concealed guns on college campuses, despite the opposition of 78 percent of polled Georgians.

In Florida, meanwhile, despite mounting incidents of vigilante justice, the Legislature not only defends the Stand Your Ground provision that was involved in the notorious shooting of the unarmed teenager Trayvon Martin, but it is actively considering other risky measures.

One would allow schoolteachers to pack firearms in class. Another, an amendment to the Stand Your Ground law, would give legal protection to Floridians who fire warning shots in the name of self-defense — a reaction to a domestic-dispute case in which a wife faces heavy prison time for firing at, and missing, her husband. The latter is just the latest in Florida’s steady stream of aberrational gun cases that have surfaced since the law was enacted in 2005, leading 21 other states to do the same.