Those who oppose minor and perhaps reasonable expansions to the power of the government on the grounds that that power will inevitably be expanded abused are not necessarily committing the fallacy of the slippery slope. Extensive precedent has shown that once any task is institutionalized in a government agency, it will forever have a lobby which is dedicated to expanding its purview and budget. No matter how rigidly and narrowly the original mission is defined, the continuing employment and power of the bureaucrats responsible for it becomes an end in itself. Perhaps one of the simplest examples of this is the list of United States Federal Agencies.
Operating independently of market constraints, the bureaucrat has no obligation to prove his efficacy or any continuing need for his services, nor any need to balance the value of the service he provides against the cost. He works tirelessly to find new crises which must brought under his control or to worsen (usually by means of perverse economic incentives) the very problem he is tasked with solving.
In the aggregate, the mass of bureaucrats in any given society work subvert the energy of the remaining productive people until civilization disintegrates into hyperinflation and bankruptcy. Their intentions may initially be purely benign, but their work requires ever greater degrees of evasion and mass brainwashing as they search for victims and enemies in ever wider circles of society.
No matter how trivial the problem to the solved, once a political solution is attempted, the issue can only be expected to become worse and more expensive. Can you think of a single instance when a bureaucracy resolved the issue it was tasked with solving and fired itself?
It should be noted that this trend also manifests in large corporations, whenever it becomes so large and vertically integrated that individual departments are able to operate outside the pressure of the market and thus outside the pricing mechanism as a means of valuing services. Fortunately, the wealth destruction of corporations in a free economy is limited by its revenue, and it need not exhaust the entire wealth of a society in order to it collapse.