But the change in schedule for the tax bill is at least the third time this year that Senate leaders paused action to accommodate ailing colleagues. It is now clear that the large number of older senators in positions of power is taking a toll on the operations of Washington.

First came the unsuccessful repeal effort of the Affordable Care Act, delayed until McCain returned to Washington following his initial diagnosis and surgery. McCain is currently recuperating at Walter Reed National Military Medical Center from the side effects of chemotherapy and radiation.

In mid-October, Senate Majority Leader Mitch McConnell (R-Ky.) waited out Cochran’s return from a debilitating urinary tract infection to pass a budget that was essential to setting up the framework for passage of the tax plan.