WASHINGTON — Senate Democrats passed a landmark health care bill in a climactic Christmas Eve vote that could define President Barack Obama's legacy and usher in near-universal medical coverage for the first time in the country's history.

The 60-39 vote on a cold winter morning capped months of arduous negotiations and 24 days of floor debate. It also followed a succession of failures by past congresses to get to this point. Vice President Joe Biden presided as 58 Democrats and two independents voted "yes" this morning. Republicans unanimously voted "no."

The tally far exceeded the simple majority required for passage.

The Senate's bill must still be merged with legislation passed by the House before Obama could sign a final bill in the new year. There are significant differences between the two measures, but Democrats say they've come too far now to fail.

Both bills would extend health insurance to more than 30 million more Americans.

Negotiations between the House and Senate to reconcile differences between the two bills are expected to begin as soon as next week. The House bill has stricter limits on abortion than the Senate, and unlike the House, the Senate measure omits a government-run insurance option, which liberals favored to apply pressure on private insurers but Democratic moderates opposed as an unwarranted federal intrusion. Obama has signaled he will sign a bill even if it lacks that provision.