The U.S Capitol at sunset in Washington, on Sept. 30, 2021. Year-end pileups of crucial legislation and the brinkmanship that goes with it are annual rituals for Congress. But this time, testy lawmakers are barreling toward an autumn of battles that are striking for the risks they pose to both parties and their leaders. Miscalculate and there could be a calamitous federal default, a collapse of Biden's domestic agenda and, for good measure, a damaging government shutdown. (A…

October 11, 2021