Great point about what Adams is actually arguing! Of course, I know the country was founded as/is a Constitutional Republic, but it's always interesting to see how much our modern (American) understanding of democracy differs from how the founders understood it – and also how they shaped the fact that most of us now equate Constitutional Republic with the best form of democracy.
Define "most" and "us".
If us means humans living in democracies, I would say that parliamentary democracy has more supporters and constitutional republics.
And even if us == the US, I would argue that most US citizens actually have only a very hazy idea about how their own system of government works, much less how others work. Most of these people think that chanting "USA, USA" in unison is democracy.