To Senate Republicans, John McCain is a real-life hero, a leader and a trusted voice who speaks his mind in the often muddled milieu of Washington politics.
He is also a crucial vote in their slim 52-seat majority.
McCain’s sudden absence from the Senate as he battles brain cancer complicates the Republican leadership’s already difficult route to ushering its agenda through Congress.
With just two votes to spare, every senator matters. McCain’s inability to flash his trademark thumbs up or thumbs down when he strides into the chamber to cast his vote could seriously stymie the Republicans on key legislation.
The first test will come early next week. Senate Majority...