The ancient legend of Robin Hood has been endlessly adapted across all artistic media and its politics bent and readjusted just as endlessly. In 1973, the Disney studio reframed the legend and repopulated it with animal characters, their accents indicating class and character traits rather than nationality (almost all of the nobility have British accents, while the peasant characters tend to have American accents). Like many Disney films based on fairy tales and British and Chinese legends, including The Sword in the Stone, Cinderella, Sleeping Beauty, and, most interestingly, the Disney Renaissance films The Beauty and the Beast, The Little Mermaid, Aladdin, and Mulan, there is an unquestioning adherence to the ancient idea of a monarchy ordained by God. Since most of these films operate under a dualistic good v. evil morality, the "rightful" heir to the throne is invariably a good guy, while pretenders are bad guys. Robin Hood also bows to this view, which is, of course, deeply embedded in the mythology of Robin Hood, and necessary if he is to be framed as a hero.
The fact that the government is a monarchy however is less important than how good and evil within governance is defined. King Richard's style of governance is largely unexamined, since he doesn't arrive until the final scene in the film. We're told that he pardons Robin Hood, imprisons Prince John and his cronies, sentencing them to hard labor (they're last seen in a shallow quarry pit), and presides over the wedding of Robin and Marian. His departure for the crusades is explained in this version as the result of hypnosis - Prince John's adviser Sir Hiss apparently convinced him to leave by hypnotizing him, therefore leaving the way open for John to seize the throne. His "crazy crusade" is thus rendered a mark of fallibility, a foolish undertaking, but not a blameworthy one. Richard is the "good" king primarily because he holds the right of inheritance, while Robin is a "good" man because he is a loyal partisan in favor of Richard.
Prince John's style of governance is characterized as evil, firstly because it is "unnatural." As long as Richard is alive, John can be no more than regent. The fact that he aspires to hold the throne himself delegitimizes his regency in the eyes of his subjects, though in actuality he has the full right to rule in Richard's absence. John's villainy is expressed by his paranoia, his ineptitude, his temper tantrums, and his mother fixation. At bottom, John is "the phony king of England" because he's childish. But his most salient policy, as well as the one his subjects object to most vociferously, and the one against which Robin works most tirelessly, is John's continually escalating taxation.
The sheriff of Nottingham is primarily, in his own words, "your friendly neighborhood tax collector," and he's portrayed stealing money from Robin disguised as a blind beggar and snatching it from a crippled blacksmith, the church poorbox, and a six-year-old bunny, who was given a farthing for his birthday. Those unable to pay their taxes are chained and imprisoned, with some offenders sentenced to hard labor. John, meanwhile, hoards the tax money, even sleeping with it. The role of government under Prince John is to acquire as much money possible and spend as little as possible. Taxation is thus, within the world of the film, a malevolent manifestation of greed and miserliness.
Other Robin Hood adaptations have approached the issue of John's fitness to rule differently. In the greatest Robin Hood film, The Adventures of Robin Hood (1938) starring Errol Flynn, Olivia de Havilland, and Basil Rathbone, Prince John does indeed squeeze the peasantry with ludicrous taxation, but his motive is not a simple matter of greed. There is a strong prejudicial element to John's policies in this version. The Saxons, of whom Robin is one, are oppressed by the heavy taxation, to the point of starvation, and they face brutal, often lethal, punishment for petty crimes, in contrast to the Normans, who enjoy greater freedoms and lower taxes. Marian, a Norman, is convinced to take Robin's side when she observes the misery of the Saxon peasants. Furthermore, John excuses the absurd tax rates with the claim that he needs it to ransom Richard, taken prisoner by an Austrian rival; naturally he has no intention of paying any such ransom. Thus, in this version, the taxation itself isn't the problem; ethnic oppression, in the service of ambition and deception, is the real root of John's evil.
These complications are not present in Disney's Robin Hood. All subjects to the English crown, barring those few like Sir Hiss who enjoy the dubious and changeable favor of Prince John, suffer under the taxation. The misery is universal. But, Prince John takes his paranoid need to destroy Robin to such great heights of evil that he proves himself a poor monarch. He plans to lure Robin into a trap by hanging Friar Tuck (in most versions, it is Robin, rescued by the Merrie Men, who risks the noose). This is, obviously, a nasty plan indeed, but Sir Hiss explicitly registers his shock that John could consider executing a man of the church. This attack on the clergy is framed as a moral wrong because of Friar Tuck's position as a spiritual leader - not because hanging itself is bad - and proves John's undoing.
Thus, the two main expressions of Prince John's badness and unfitness to hold the throne are his tax policies and his failure to hold the church sacred. These are deeply conservative sins, but while the first is certainly in tune with American libertarian politics, the second is absolutely not. The expressed politics of Disney's Robin Hood are not libertarian, but there is a strong libertarian shading that may prove rather disturbing to those who may not want their children to grow up believing that paying taxes is a form of evil social oppression. One also hopes that children watching the film come away simply convinced that death by hanging is an appalling thing, but the film in fact doesn't condemn capital punishment: it condemns capital punishment for "untouchable" authority figures. Overall, Robin Hood's moral simplicity lands it squarely in the conservative camp, both fiscally and socially.