A tale of two blowhards The Brits show that a political party doesn’t have to blindly back its leader even when he’s popular: An angry, aggrieved former leader attacks the institutions he once led for accusing him of flouting the rules and lying about it. His allies whip up supporters against what they call a witch hunt. A country watches nervously, worried that this flamboyant, norm-busting figure could cause lasting damage. There are obvious parallels in the political tempests convulsing Britain and the United States, but also stark differences: Former President Donald J. Trump faces federal criminal charges while Boris Johnson was judged to be deceitful about attending parties. And yet, Britain’s Conservative Party has regularly stood up to Mr. Johnson while the Republican Party is still mostly in thrall to Mr. Trump. Conservative lawmakers in Britain form the majority on a committee that found Mr. Johnson, a former prime minister, had deliberately misled Parliament over lockdown-breaking parties in Downing Street during the coronavirus pandemic. Mr. Johnson’s conduct, they said, would have warranted a 90-day suspension from the House of Commons had he not preemptively resigned his seat in protest last week. On Monday, the House of Commons will vote on whether to accept or reject the committee’s findings. The government said it would not pressure Tory lawmakers to vote one way or the other. That sets up a potential repudiation of Mr. Johnson by his party that could go far beyond the token number of Republican lawmakers in the House of Representatives who voted…