A tense first round of the Covid hearings committee

In the martial art of muay thai, fighters often do not know their opponent before they face off. The opening rounds are typically tight affairs, with each fighter studying the other’s strengths and weaknesses. Meanwhile, in MMA, fights are often scheduled weeks or months in advance, rules are at a minimum, and the two competitors go straight at each other’s throats from the opening bell. In the first session of the Brazilian Senate’s hearings committee to investigate the government’s pandemic response, the battle lay somewhere in between these two extremes: neither cagey and measured, nor an all-out slugfest.

In one corner of the congressional ring stood Senator Flávio Bolsonaro, the president’s eldest son. In the other, the investigation’s rapporteur Senator Renan Calheiros. Their sparring before and during the committee’s first session gave us a glimpse of what to expect over the next 90 days.

There is plenty of bad blood between Mr. Calheiros and the Bolsonaro family, dating back to 2019 when the president led a campaign to prevent him from being elected Senate President. Things got worse on Monday, when government allies filed a lawsuit claiming that Mr. Calheiros could not be selected as rapporteur based on the principle of “administrative morality.” The senator faces a long list of corruption accusations.

Initially, a trial court judge issued an injunction against Mr. Calheiros. Soon after, the Senate responded that the decision was unfounded, and that the upper house would simply ignore the order until it was overturned...