How Republics Die!

The Roman Republic didn't die suddenly when Julius Caesar crossed the Rubicon with some of his veteran Legions in 49 BC. The Republic, over the previous four decades had suffered through five civil wars, a major servile uprising (Spartacus), and an attempted coup d'etat, all of which Caesar had witnessed or participated. Caesar didn't so much kill the Republic, as he finished it off and buried it. The Roman Republic suffered from several terminal diseases. Enormous wealth had undercut Romans commitment to Republican principles. Holding public office had become less a demonstration of service, and more a means to enrichment and power. And as the stakes increased dramatically, political defeat meant not only personal failure but also personal and family ruin, and even death! Caesar had only narrowly escaped execution after his faction suffered defeat in Sulla's 2d civil war.
The prospects of enormous wealth in our American Republic have likewise corrupted our politics, and more recently political defeat has threatened to involve investigation, prosecution, and prison.
Are we on the same trajectory as the Roman Republic?