Interesting and rousing document. When taking the historical context into account, it is not hard to see why 'Common Sense' had the impact it did. From a modern perspective though, parts of Paine's text are problematic for a number of reasons. Some sections (especially the part about military and naval affairs and numbers) are as dry as the paper it's printed on, though that is hardly surprising considering 'Common Sense' was written almost two and a half centuries ago. Other issues are racism, anti-Catholic bias and hypocrisy. Paine makes one of his points against the monarchy by arguing that since England was conquered by Frenchman William the Conquerer, the current royal line is unlawfully in power since that power stems from invasion against the will of the native (Anglo-Saxon) population. Yet, Paine conveniently forgets the native population of the Americas and the fact that they were invaded against their will too. He goes even further, suggesting that 'Indians and Negroes' are 'stirred up to destroy us' by Britain, generalizing and reducing whole peoples to enemies of the Revolution (which in itself is incorrect since both Native Americans and African-Americans fought on both sides during the Revolutionary War). Also, Paine argues for Freedom of Religion, but at the same time expresses strong anti-Catholic bias, equating the concept of monarchy (the form of government he considers wrong and evil) to 'Papism'.
Most of this is in keeping with the mores of the times, but it still bothers me. Especially the hypocrisy with which Paine, populist-like, tries to set his white, European and Protestant Americans apart from everyone else.
Still, 'Common Sense' contains some interesting political ideas, makes a good case for independence, and sheds a lot of light on the Revolutionary sentiments in Revolution-era America.