John Boehner’s looming departure from the House leadership stems from his frustration at leading his Republican caucus, particularly its implacable obstructionists who refused to be led. Farewell tributes have highlighted Mr. Boehner’s folksy decency and bought into his self-description as the grown-up in a legislative playpen. By this account, he was undone by Tea Party toddlers who were endlessly willing to be stupid or destructive to get their way or make a point.

Intimidated by the awesome power of no, Mr. Boehner gave up.

Mr. Boehner is free of them now. And so now is his chance. In the days he has left, he can revive immigration reform. He can pass the large-scale, comprehensive overhaul that lawmakers had worked on for years, a bill that passed the Senate in 2013 with strong bipartisan support and could have been sent to President Obama’s desk but for the obduracy of the nativist right in the House and Mr. Boehner’s unwillingness to call a vote.

What would have happened if reform had passed? It was the best chance in a generation to modernize a collapsed immigration system, to put the country’s future on a sounder footing, to finally resolve the status of 11 million people whose potential as taxpaying citizens is bottled up by fear and hopelessness. It would have been a boon for the economy, and for Mr. Boehner’s party. It would have averted Mr. Obama’s controversial executive actions on immigration, which he took as a last resort in the face of congressional abdication.

It would have made the country a better place, a place more welcoming and sensible about immigrants, and truer to its values of assimilation and integration.