Millions of low-income Americans won’t receive coverage. Many workers at small businesses won’t get a choice of insurance plans right away. Large employers won’t need to provide insurance for another year. Far more states than expected won’t run their own insurance marketplaces. And a growing number of workers won’t get to keep their employer-provided coverage.

Every branch of the federal government played a role in weakening the law over the past three years, the casualty of a divisive legislative fight, a surprise Supreme Court ruling, a complex implementation and an unrelenting political opposition. The result has been a stark gap between the promise of Obamacare and the reality — one that has fueled a deep vein of skepticism about the law as it enters its most critical phase. …

His best defense against Republican repeal efforts is a robust consumer response, and his best hope to soften years of public antipathy is a successful rollout. That’s why Obama is asking millions of Americans to just give the law a chance — go to the Web, sign up for a health care plan starting Oct. 1 and claim a new benefit that’s there for the taking on Jan. 1. It’s also why Republicans are mounting such an aggressive last stand this week to revoke funding for the law.