The death of the American mule.
Like Animal Farm's Boxer, the American workhorse has worked itself to the bone, paying taxes on everything imaginable to subsidize the revolutionary state of the left, its mammoth bureaucracies and the bribes and favors that it doles out to its voting bases. Homes have been lost, lives shattered and families broken up so that America might "live up to" whatever promises the left has made to itself on their behalf. And like Boxer, the American and his way of life, is being taken away in a knacker's van billed as a trip to the veterinarian.
The left has forcefully accelerated the death throes of the American mule by pushing government spending beyond anything that the horse can cover. That leaves the overworked horse with only two options. It can either become a donkey and be fed and work without any say in what it is fed or how it works, or it can try to break free of the great socialist boneyard.
His essay/post summarizes many or most of the Maggie's political concerns about America. The government is making it too difficult to be a mule, but it is the mule who pulls their electoral wagon and pays their bills.