Earlier quoted context omitted.
The deer themselves are a problem in the northeast. They are greatly overpopulated and eat the native understory, preventing the next generation of trees from growing past adolescence. As the existing trees slowly die, there will be none younger to replace them. This also clears out the competition to the benefit of non-native plants, which the deer don't eat. Some of these plants are invasive, such as japanese barbe…
The mice are the main component to the lyme lifecycle. There is a researcher working to give mice immunity using crispr. Generally, the deer are only overpopulating (at least to the extent you describe) in areas that aren't hunted, which also tend to be highly populated. It seems many people enjoy seeing the deer in their backyards and don't want their almost-pets to be killed, especially if it means it might have to…
You could also get more ppl into gardening. Gardeners end up hating deer after their gardens get raided once or twice.