After over a decade in power, a leftist party is damaged by corruption allegations. A weakened economy and parlous public finances add to public disaffection. Mounting fears over street crime fuel a sense of crisis. Challengers on the right, promising a clean-up and a crackdown, capture public attention—and eventually the presidency.

The same broad-strokes scenario has played out over the past 18 months across much of Latin America, notably in Argentina, Chile and Brazil. And with under a year until presidential and congressional elections in October 2019, a similar story—albeit with characteristic understatedness—is unfolding in Uruguay, the Southern Cone’s final outpost of the “pink tide” that swept left-wing leaders to power in the early years of this century. ...