Maine Republican Susan Collins is one of the last centrists in the Senate

JUST OFF THE SOARING, TOURIST-FILLED rotunda of the U.S. Capitol building, down a chandeliered hallway, up a few floors in what feels like the world’s tiniest elevator, in a narrow, echoing corridor, lies the hideaway of Senator Susan Collins. The private office, a perk doled out by seniority, is appointed in creams and florals and feels warm but not exactly homey. Most of all, it is secluded—no staff, no uninvited visitors, no constituents. And it was in this hidden space in late September that the Republican from Maine weighed one of the most divisive decisions of her 21-year career in Congress: whether to vote to confirm Brett Kavanaugh to the U.S. Supreme Court.

Months later, artifacts of that episode are still visible. Two newspapers with reports on Kavanaugh’s