The coming weeks will define Biden's presidency and shape the midterm elections

President Joe Biden must define the politics of this fall before they define him, as he seeks to re-establish the authority of an administration that often appeared overtaken by a relentless summer of challenges.

The weeks following Labor Day will reveal answers that will set the stage for next year's congressional elections. They will also help decide whether Biden has the potential for a historically significant presidency or gets swamped by the crises he was elected to conquer. A crush of challenges and political battles are dominated by a pandemic Biden hoped would now be history. But the crisis is beginning to feel endless, and, as it batters national morale, is denting his political standing. The fallout from a chaotic exit from Afghanistan that encapsulated the ignominy of a US defeat is meanwhile raising questions about Biden's core promise of competency. The internal Democratic Party tussle between progressives and moderates is highlighting the huge bet of the Biden presidency: That, at a time of national crisis, voters want a multi-trillion-dollar assault on climate change and the remaking of the social safety net.