WASHINGTON — Senate Democrats won a crucial test vote on President Barack Obama's health care overhaul, putting them on track for passage before Christmas of the historic legislation to remake the nation's medical system and cover 30 million uninsured.

All 58 Democrats and the Senate's two independents held together early today against unanimous Republican opposition, providing the exact 60-40 margin needed to shut down a threatened GOP filibuster.

The vote came shortly after 1 a.m. with the nation's capital blanketed in snow, the unusual timing made necessary to get to a final vote by Christmas Eve presuming Republicans stretch out the debate as much as the rules allow. Despite the late hour and a harshly partisan atmosphere, Democrats' spirits were high.

"Today we are closer than we've ever been to making Sen. Ted Kennedy's dream of universal health insurance coverage a reality," Sen. Tom Harkin, D-Iowa, said ahead of the vote, alluding to the late Massachusetts senator who died of brain cancer in August.

"Vote your hopes, not your fears. Seize the moment," Harkin urged colleagues.

The outcome was preordained after Senate Majority Leader Harry Reid, D-Nev., wrangled his fractious caucus into line over the course of the past several months, culminating in a frenzy of last-minute deals and concessions to win over the final holdouts, independent Joe Lieberman of Connecticut and conservative Democrat Ben Nelson of Nebraska.