A new analysis that at least 18 million people could lose health insurance in the first year if Congress repeals the Affordable Care Act without replacing it intensified the battle this week over the landmark healthcare law as US President-elect Donald Trump and Republicans try to figure out how to dismantle it. Democrats seized on the report, issued by the nonpartisan Congressional Budget Office, to discredit Republican efforts to repeal Obamacare and rally Americans who are insured under the programme.