WASHINGTON (AP) — President Donald Trump's abrupt move to cut off federal payments to insurers jolted America's health care and political worlds alike on Friday, threatening to boost premiums for millions, disrupt insurance markets and shove Republicans into a renewed civil war over their efforts to shred "Obamacare."

Defiant Democrats, convinced they have important leverage, promised to press for a bipartisan deal to restore the money by year's end. That drive could split the GOP. On one side: pragmatists seeking to avoid political damage from hurting consumers. On the other: conservatives de...