WASHINGTON (Reuters) - Republican U.S. Senators Lindsey Graham and Bill Cassidy said on Thursday they were working with Republican Senator Ron Johnson and members of the House of Representatives to add more “flexibility provisions” to a proposed bipartisan bill to stabilize the healthcare insurance market in the short term. They said in a statement these provisions were needed to win support in the House for the stabilization measure introduced by Republican Senator Lamar Alexander and Democratic Senator Patty Murray to shore up the insurance markets created under the 2010 healthcare law by reviving subsidies for two years to help lower-income Americans obtain medical coverage. President Donald Trump said last week that he was discontinuing the subsidies. [nL2N1MU1CS]  