U.S. Senate Democrats on Thursday blocked legislation meant to kill the Iran nuclear deal for a third time, securing perhaps the greatest foreign policy win of President Barack Obama’s six years in office and clearing the way to implement the accord. By a 56-42 vote, the Republican-majority Senate fell short of the 60 votes needed to advance in the 100-member chamber. Despite an intense and expensive lobbying effort against it, all but four of Obama’s fellow Democrats backed the nuclear pact between the United States, five other world powers and Tehran announced in July. With no more Senate votes this week, the result ensured Congress will not pass a resolution of disapproval that would have crippled the deal by eliminating Obama’s ability to waive many sanctions. […]