WASHINGTON — President Obama’s tax package easily cleared its first hurdle Monday, with the Senate voting overwhelmingly to move forward with the bill. But the real battle awaits in the House.

The final Senate tally was not known late Monday night because the vote was being kept open for several hours to accommodate senators whose travel was delayed by a Midwestern snowstorm. But with about two-thirds of the chamber voting, the measure passed the 60-vote threshold late Monday afternoon.

The procedural vote clears the way for a final vote today on the package, which Obama negotiated with Republicans and would prevent tax-rate increases from hitting most American workers starting Jan. 1.

After it became clear the Senate would move forward, Obama said at a news conference that the vote shows what the two parties can accomplish when they come together. He urged quick action from the House, where Democrats and some Republicans have proved more resistant to the deal.

“I recognize that folks on both sides of the political spectrum are unhappy with certain parts of the package, and I understand those concerns. I share some of them,” Obama said. “But that’s the nature of compromise – sacrificing something that each of us cares about to move forward on what matters to all of us.”

Despite Obama’s urging, liberals have balked at the compromise, and the Democratic caucus resolved last week to prevent the bill from getting to the House floor.

The package would extend for two years all the income tax cuts approved under President George W. Bush. It also would continue long-term unemployment benefits for 13 months; provide a generous incentive for companies to invest in new equipment in 2011; and reduce the payroll tax for individuals from 6.2 percent to 4.2 percent for one year. Obama sought the last two provisions to accelerate the economic recovery.

The main component of the compromise is the extension of the Bush tax cuts. While Democrats wanted to avoid renewing the tax cuts on income above $250,000 per family, Republicans wanted a permanent extension of all the cuts.

But Rep. Chris Van Hollen, D-Md., soon to be the ranking member of the House Budget Committee, said Sunday that the main sticking point is the change in the estate tax, which taxes the transfer of funds from a deceased person to his or her beneficiaries. The legislation would exempt estates valued at up to $10 million from a newly imposed tax.

Van Hollen said on Fox News Sunday that he expects some form of compromise to come to a vote, but many Democrats want alterations to the package.

“Most of us agree with almost all of what the president negotiated,” Van Hollen said. “There is one thing that just was the choking point, and that deals with the estate-tax break.”

Van Hollen added, “We’re not going to hold this thing up at the end of the day.”

Despite the Senate’s key vote Monday, there is still opposition in that chamber. Sen. Bernie Sanders, I-Vt., who staged an eight-hour filibuster of the bill Friday, voted against the package Monday.

Sanders was joined by at least eight other senators, all Democrats: Carl Levin of Michigan; Jeff Bingaman of New Mexico; Russ Feingold of Wisconsin; Kirsten Gillibrand of New York; Sherrod Brown of Ohio; Patrick Leahy of Vermont; Kay Hagan of North Carolina; and Mark Udall of Colorado. The lone Republican to vote no was Sen. John Ensign of Nevada.