With the last-minute support of anti-abortion colleagues, House Democrats on Sunday passed historic legislation to extend health coverage to tens of millions of uninsured Americans, protect patients from the most flagrant abuses of insurance companies, and curb runaway health care costs. All told, the $940 billion reforms represent the most sweeping overhaul of the nation’s health care system since the creation of Medicare more than four decades ago. The tally was 219 to 212 in support of reforms passed by the Senate on Christmas Eve, with 34 Democrats joining every Republican in the lower chamber in opposition to the measure.