The best thing the New York Times puts out is The Interpreter, which for some jackass reason they don't have on their website.

Some of the gravest democratic collapses, Mr. Ziblatt and his co-author, Steven Levitsky, found, occurred in 20th century South America, whose two-party presidential systems closely resemble that of the United States. And the downward spiral began, more than once, with the party in power twisting unwritten but important norms to take control of the country’s highest court.

In Argentina, the president’s party abused its power to replace Supreme Court justices, installing loyalists in three out of the court’s five seats. In Venezuela, President Hugo Chávez packed the court, adding a dozen new judges. Chile provides perhaps the most worrying example: Though the precise norm-breaking was different, it led to a cycle of escalation between the parties until the country — long seen as akin to the United States in its democratic longevity and stability — collapsed into violence and dictatorship.

Chile’s bloody fate was also the product of Cold War meddling and polarization that don’t exist in today’s United States. But the pattern is disturbingly familiar. One party violates those norms to give itself a structural advantage beyond its share of the vote. The other side follows suit. Eventually, the norms are gone and with it democracy as we commonly understand it.

Scholars have a term for this kind rule-twisting that exploits unwritten norms for short-term political gain: constitutional hardball.

Any politician faces a temptation to break unwritten norms for short-term gain. The expectation is that they’ll restrain themselves out of a belief that preserving the system is more beneficial in the long-term and that voters or their peers may punish them for drastic transgressions.

But when that logic fails and parties come to see hardball as worth the risk, it can, in extreme cases, set off a doom spiral that can be hard to recover from.

Imagine a baseball game where one team begins breaking rules and faces little consequence. This forces the other team into a difficult choice. It can continue following the rules in the hopes that its opponents will voluntarily give up their rule-breaking advantage. Or it can even things out with its own rule-twisting, knowing this might set of a cycle of tit-for-tat escalation until they’re not even really playing baseball anymore so much as just brawling in the outfield.

There’s a reason that fights over the nation’s high court are often what tip shaky democracies into outright collapse: It’s an opportunity for one team to appoint the umpires who oversee the game....

“If you have one of the two parties in a two-party system not committed to the rules, your system is really in trouble. There’s just no way out of that,” Mr. Ziblatt said. Asked if he knew of any democracies where this had happened and the system had recovered, he paused for several moments before answering, “No. Just no.”