The fourth, and arguably most critical, open enrollment period kicked off Tuesday amid an increasingly contentious political debate over the future of the Affordable Care Act, with GOP presidential candidate Donald Trump reasserting his pledge to repeal the law while ACA supporters worked to ensure the administration can meet or exceed its goal of 13.8 million signs ups. Trump pledged to convene a “special session” of Congress to work on repealing the law if elected president, but did not elaborate...