The spotlight was on moderate Democratic Senator Ben Nelson of Nebraska, who had been the last holdout as Senate Democrats raced against the clock and against determined Republican opposition to pass their health care bill by their self-imposed deadline of December 25th, Christmas.
Nelson said he is now ready to vote for cloture, which would advance the bill.
"Change is never easy, but change is what is necessary in American today and and that is why I intend to vote for cloture, I intend to vote for cloture and for health care reform," he said.
Nelson said he decided to support the bill after winning new concessions from Democratic Senate Majority leader Harry Reid to limit the availability of abortions in insurance sold under the new legislation.
The legislation would extend health benefits to more than 30 million uninsured Americans and impose new regulations on the health insurance industry.
Senator Reid of Nevada has been working for months to win over one holdout Democratic senator after another, repeatedly altering the bill to satisfy different demands. Reid says reform is essential. "The broken system cannot continue and it will not continue. When President Obama signs this bill into law, we will officially end the era in which insurance companies win only when patients lose," he said.
Nelson's support should pave the way for Senate Democrats to win the first of a series of crucial procedural votes scheduled to begin at one o'clock in the morning (0600 GMT) Monday and set to conclude - if everything goes smoothly for them - with final passage on Christmas Eve.
Republicans have been using a number of parliamentary procedures to delay action on the bill, including forcing a reading on the Senate floor Saturday of Reid's 338-pages of last minute amendments. Republican Minority Leader Mitch McConnell responded to the apparent Democratic breakthrough. "And Democrats are forcing a vote on it, as I indicated, over the weekend, counting on the fact that the American people are preoccupied with Christmas and not paying much attention to what they are doing," he said.
Republicans are unified in their opposition, saying the bill is too expensive and will not solve the problems with the current health care system. Senator McConnell dismissed claims by Democrats that the bill is historic. "The history that is being made here, make no mistake about it, the history that is being made here, is the ignoring of the will of the American people," he said.
Democrats say they have been trying to reform the nation's health care system for close to 70 years, ever since President Franklin Delano Roosevelt was in office. Senator Christopher Dodd of Connecticut was emotional as victory seemed within reach. "All we are trying to do is to guarantee that if you are a fellow citizen of ours, and you are struck with illness or a loved one is, that you will never again have that fear, that you will end up losing your home, your job, your retirement and your life savings because you have been afflicted with an illness through no fault of your own."
If the Senate is able to pass a bill next week, it would be viewed as a major victory for President Obama. But the bill would still need to be reconciled with a health-care reform bill passed last month by the House of Representatives before the president could sign it into law next year.