The argument concludes that a hunting ban put in place in Greenfield County eight years ago was unnecessary to promote public safety, and also created a new threat to public safety. This threat is the large deer population, which we learn has expanded to six times its pre-ban size. To support the deer being a threat, the argument says that the deer are causing property damage and car accidents that injure motorists. To support the ban being unnecessary, the argument points out that the county had no hunting-related injuries before the ban.

We're looking at a causal argument using phenomenon-hypothesis reasoning. The argument observes the phenomenon of deer overpopulation, and puts forward the hypothesis that this was caused by the hunting ban, leading to deer-related public safety issues. The other prong of this argument is the observation that there were no previous hunting-related injuries, supporting a hypothesis that hunting was not a public safety threat.

Since we're dealing with a phenomenon-hypothesis argument with two separate branches, we can aim to strengthen either hypothesis: that the ban caused the deer overpopulation, or that hunting wasn't a threat. Either of these causal claims can be strengthened by finding corroborating evidence, or by ruling out an alternative explanation.