Although populist figures are often thought to thrive during crises that allow them to ‘perform’ decisive leadership, the US experience under Donald Trump during the COVID-19 crisis demonstrates that the opposite may sometimes occur. Despite its scientific and medical prowess, the US suffered more coronavirus cases and deaths than any other country in the world during the first year of the pandemic, and this abysmal performance was largely attributable to a failure of government. Fixated on the pandemic's economic effects and its potential political fallout, the Trump administration's framing of the crisis tried to minimize the public health emergency, externalize blame through a focus on the Chinese scapegoat and accuse the media and Democrats of hyping the pandemic to undermine Trump's presidency. In responding to the pandemic, Trump and his allies cast doubt on scientific and medical expertise that called for more aggressive testing, mask wearing and social-distancing measures. Trump delegated responsibility for crisis management to subnational governments and the private sector, and he politicized their efforts to regulate social behaviour in the public interest, intensifying partisan polarization.

When and why do legislatures impeach presidents? We analyse six cases of attempted impeachment in Paraguay, Brazil and Peru to argue that intra-coalitional politics is central to impeachment outcomes. Presidents in Latin America often govern with multiparty, ideologically heterogeneous coalitions sustained by tenuous pacts. Coalitions are tested when crises, scandals or mass protests emerge, but presidents can withstand these threats if they tend to allies’ interests and maintain coalitions intact. Conversely, in the absence of major threats, presidents can be impeached if they fail to serve partners’ interests, inducing allies to support impeachment as acts of opportunism or self-preservation.

Polarization may be the most consistent effect of populism, as it is integral to the logic of constructing populist subjects. This article distinguishes between constitutive, spatial and institutional dimensions of polarization, adopting a cross-regional comparative perspective on different subtypes of populism in Europe, Latin America and the US. It explains why populism typically arises in contexts of low political polarization (the US being a major, if partial, outlier), but has the effect of sharply increasing polarization by constructing an anti-establishment political frontier, politicizing new policy or issue dimensions, and contesting democracy's institutional and procedural norms. Populism places new issues on the political agenda and realigns partisan and electoral competition along new programmatic divides or political cleavages. Its polarizing effects, however, raise the stakes of political competition and intensify conflict over the control of key institutional sites.