Large cities have attracted immigrant groups who (ahem) have found it hard to adapt and support themselves, and none of them have been from much of a tradition other than monarchies and other forms of despotism; since the 19th c political machines have had success in building a permanent hold on all the other anti-democratic forces, such as ‘labor’ unions and the Mob (and sometimes that’s redundant).
Truman came from Missouri, which was largely rural in his day, and yet owed his own political rise and career to the Pendergast machine. It’s been written that Truman helped bring him down, but that’s a bit of a story. Truman also was a teaching example for the three kinds of memory — Long Term, Short Term, and Convenient Memory. And he was a rabid single party state Demwit.
Truman couldn't succeed as a farmer or businessman so by middle life decided life as government clock puncher was for him. It's remarkable how unaccomplished most of the Democrat machine cogs really are. Barky and Harry have a lot in common, except Harry wasn't an urban media project.