Senate Majority Leader John Thune (R-South Dakota), from left, Sen. John Barrasso (R-Wyoming) and Senator Mike Crapo (R-Idaho) exit the West Wing of the White House on June 4, 2025. The Senate has begun deliberations over President Donald Trump’s massive “Big Beautiful Bill” that narrowly passed the House on May 22, with several Republican senators expressing concerns over its cost as well as cuts to Medicaid and clean energy tax credits.Photographer: Eric Lee/Bloomberg via Getty ImagesRepublicans on Capitol Hill are weighing legislation that’s estimated to cut billions of dollars of funding for the Affordable Care Act and cause millions of people to lose their health insurance. Many of their constituents may not be happy about it, polling suggests.Nearly half, 45%, of adults enrolled in a health plan offered through the ACA insurance marketplace identify as Republicans, according to a new survey by KFF, a nonpartisan group that conducts health policy research.(More than three-quarters of those Republican ACA users identify as “MAGA” Republicans. Those MAGA Republicans represent 31% of ACA purchasers overall.)Meanwhile, 35% of Democrats get their health insurance through the ACA, KFF found.[embedded content]Republicans in the House of Representatives passed a multitrillion-dollar tax and spending package in May estimated to cut about $900 billion from health programs like Medicaid and the ACA, which is also known as Obamacare.Senate Republicans are now considering the measure, which contains many of President Donald Trump’s domestic policy priorities. Republicans are trying to pass the megabill by the Fourth of July.If the GOP enacts the legislation as written and doesn’t extend tax credits that lower monthly ACA health premiums, about 15 million people would lose health insurance, according to the Congressional Budget Office.”A large constituency of Republicans using the programs are potentially facing cuts,” said Audrey Kearney, a senior survey analyst for KFF’s public opinion and survey research program.The survey was conducted May 5 to 26 among a nationally representative sample of 2,539 U.S. adults …