I’m writing this edition of the Impeachment Briefing from snowy, frigid Battle Creek, a town of around 50,000 and the epicenter of American cereal production, where the scent of Rice Krispies and Raisin Bran sometimes wafts through the air. On Wednesday night it was a hive of pro-Trump, anti-impeachment fervor, the only time in American history when a president held a campaign rally the night of his impeachment.

Thousands of Trump supporters wrapped in scarves and parkas lined up early in the morning, some of them waving flags featuring Mr. Trump holding an assault rifle, while a large screen nearby pumped out videos the Trump campaign made with the president’s daughter-in-law, Lara. Unofficial vendors sold goods with “Trump 2020: No More,” with an expletive at the end.

Mr. Trump took the stage, before dozens of other journalists and more than 6,000 cheering supporters, around 17 minutes before his impeachment was finalized, leading to a surreal moment in the arena. About an hour in, Mr. Trump read off the vote counts, boasting about how unified Republicans were.