Interestingly (to me at any rate
) Tolkien's political preference seems to be for monarchies, with an associated class system - yet he still shows how monarchies are ineffective systems of government. It's shown to be good for the people when a King such as Aragorn is in charge, but he also shows how a greedy, lazy or simply power hungry monarch can wreak havoc - in both the appendices about Gondor in LotR and in Numenor. He also goes one step further to show how unelected officials can be incredibly corrupt, as seen in Grima's actions. Notonly does Tolkien show us these shortcomings, but he also shows us the fragilities of monarchies, how the 'line' can become confused or even lost altogether.
I'd say his 'ideal' was the monarch as demonstrated by Aragorn, but he realised that the system itself could be problematic. Though I do have to ask whether any of the political systems we see in the modern world would 'fit' in the world Tolkien created.