party chief, said people in Chongqing and Beijing, who spoke on the condition of anonymity because of the delicacy of the situation. Some analysts say the purging of Mr. Bo has presented the party’s top echelon with its biggest challenge since the Tiananmen Square protests and massacre in 1989.

The downfall of Mr. Bo, who comes from a prominent revolutionary family but acquired many enemies in his political career, began when his former police chief in Chongqing, Wang Lijun, showed up at the United States Consulate in Chengdu on Feb. 6 with what he said was evidence tying Mr. Bo’s family to Mr. Heywood’s mysterious death in Chongqing last November.high court to step in, particularly since the United States Court of Appeals for the D.C. Circuit will hold oral arguments in June and the states would not have had to come into compliance until 2018. That a divided Supreme Court stepped in at this juncture to block the program after a lower court declined to do so sends a signal that at least five justices are concerned with some aspect of the plan.

The ruling comes as Obama continues to push action on global warming as a key part of his legacy, and effort that reached its peak with the deal at the U.N.-led talks on climate change in Paris in December.

The EPA rule would require states to meet specific carbon emission reduction standards based on their individual