When the delegates from all the states came to frame a constitution, they were amazed to find all the things they disagreed on, all the issues of contention. I think it's to their great credit that they resolved all these disagreements through compromise, the idea that everyone gives something up, nobody gets everything he wants, but hopefully everyone gets something he can live with.
I don't think politicians today could do it. Today the Republicans especially seem to think that compromise is capitulation. But in those days this was how gentlemen resolved their differences.
By the end of the convention, many of the delegates believed the Constitution wouldn't last long, that it would fall apart when a majority of states decided they didn't like it, and some new arrangement would come about.
There WERE delegates who showed up at the convention wanting to establish a monarchy in the US! Most of the revolutionaries were not anti-monarchy, they just didn't like King George III. At first, the revolution began with the American colonies fighting not for independence but for rights equal to Englishmen--local control of courts and law enforcement, representation in Parliament, etc. The revolution had been going on some time already when they decided they'd rather have total independence, but that didn't mean -democracy- necessarily.
So there might even have been some legitimate question, at the end of the process, whether the delegates had created a monarchy or a republic, and how long that republic would last. I really think they'd be surprised to see the Constitution still in use 230 years later.