The need for common sense
If what Paine is elaborating is Common Sense, then why does he feel the need to convey what should be common? The answer is a humorous irony. One might choose to picture Thomas Paine frustrated by what he perceives as stupid public opinion, rubbing his temples perhaps from a migraine, and saying, "This should be common sense." That is the ultimate irony of the book, it turns out, that what is obvious and true is very often not common at all; common sense is actually quite rare.
The irony of public power
By forfeiting their individual power, Paine argues that the public becomes more powerful, insofar as they select a government that properly enfranchises their desires. To the extent that people are active in the selection of their ideal government, they are as powerful as they can get without actually joining the government by running for office. This tedious balance is the stuff that tore France apart in the same century, and this has been the schism that has undone many a nation, because the people have power despite appearances; they have the choice to overthrow their government—if they can so manage.
Elections and irony
Paine's treatment of elections is very important, because he is re-invoking classical legal philosophy. His opinion is that if every citizen is treated equally by the law, then the only fair way to do anything is through a system of votes where votes are measured and obeyed as absolute law. For instance, no party of the government of America has any authority to tamper with an election or to deny election results. They can demand a recount, but still, the government treats the election results as law.
The irony of monarchy
There is a paradoxical irony in Paine's treatment of monarchy, because he observes right away that the entire principle of monarchy seems at odds with his deist belief that all human lives are essentially equal. Yet, monarchy emerged from that very same human essence that makes men equal in the first place. Is a monarch necessary? asks Paine. He says that in fact monarchy might constitute a lower form of human government, because it has not become enlightened to the sovereignty of the human soul.
The imposition of order
Returning conceptually to the irony of Common Sense as a fairly unique are rare aspect of human consciousness, Paine does something even more ironic at the end of the pamphlet. He explains that by imposing specific and strategic rules of order, a new country could establish a brand new government from scratch. Then, he goes on to explain technically how that would work, and how various relationships between areas of America might relate to one another in federation. In other words, this "common" sense also includes a full-scale draft for the uniting of the United States.
