WASHINGTON (AP) — Congressional negotiations over a bill extending a payroll tax cut and unemployment benefits can begin as soon the Senate rejects a version the House approved despite a White House veto threat, the Senate's top Democrat said Wednesday. Senate Majority Leader Harry Reid wants his chamber to vote quickly on the House payroll tax bill, which includes Democratic-opposed spending cuts and language speeding work on an oil pipeline, to demonstrate how little support it has in the Senate. That could strengthen his hand in talks with House Speaker John Boehner, R-Ohio, over a compromise. "The sooner we put...