| Senate Majority Leader Chuck Schumer, a New York liberal, and Sen. Joe Manchin, the pivotal West Virginia centrist, have long been a prominent odd couple on Capitol Hill. It is Mr. Schumer’s job, as the Democratic leader, to keep the caucus united in the face of the pressure being piled on it from others in the Democratic Party, as he seeks to advance the Biden agenda. One obstacle to that unity is Mr. Manchin, a rare Democrat from a state that went heavily in the last two elections for former President Donald Trump and whose iconoclastic positioning on several Democratic priorities has drawn the ire of more progressive colleagues in Congress and party activists. | 
