In a victory for President Obama and his allies in the pharmaceutical industry, the Senate today turned aside a bid by a bipartisan group of lawmakers to make it easier to import cheaper prescription drugs from Canada and Western Europe -- a proposal that threatened to derail the Democrats’ landmark healthcare bill.

The vote on the amendment -- cosponsored by Sens. Byron Dorgan (D-N.D.) and John McCain (R-Ariz.) -- was 51-48, nine short of the 60 needed to pass.

The politically charged amendment held up the Senate for a week as drug companies, the White House and lawmakers from states that are home to drug makers fought to derail the proposal. Critics, including the Food and Drug Administration, said it would be difficult to implement and hard to guarantee that imported drugs would be safe.

Further adding to the momentum for final Senate approval of the massive healthcare bill, Obama and many liberal Democrats rallied behind the decision to put aside a goal liberals had long held as an article of faith -- a new government health insurance plan to compete with the private sector.

Obama summoned Senate Democrats to the White House today to urge them not to let disagreements over details of the legislation derail or delay the landmark effort.

“This reform has to pass on our watch,” the president said. “We are on the precipice of an achievement that has eluded Congresses and presidents for decades.”

While some liberals mourned the capitulation that has long seemed inevitable, leaders of several progressive groups signaled that they would support the strategy for now rather than risk stalling their drive.

“The final bill won’t include everything that everybody wants,” Obama said.

The president weighed in at a critical moment, as Senate Majority Leader Harry Reid (D-Nev.) was working to unite their party in advance of key votes on the compromise that did not include the so-called “public option” -- a new government-run health insurance plan -- or an alternative plan to expand Medicare, which was popular with liberals.

A vast array of details have yet to be pinned down, but the framework of the Senate bill came into view as Reid pushed the Senate to finish work before Christmas. The sense of gathering momentum was fueled as disputes on other issues were resolved: Behind-the-scenes negotiations continued to resolve differences among Democrats over restrictions on federal funding for abortion.

The drug amendment had in the past enjoyed broad support from Democrats -- including Obama -- but the White House and Senate leaders bowed to the pharmaceutical industry and joined their effort to derail it. The administration feared that if the amendment had passed, pharmaceutical companies, which earlier this year struck a deal with the White House to limit the economic impact of a healthcare overhaul on their industry, would turn against the broader health legislation.

To appease critics, Reid pledged this week to work with House leaders to ensure that a final bill would close the so-called Medicare doughnut hole, a gap in prescription drug coverage that forces millions of seniors to pay for thousands of dollars of drugs out of their own pockets.

On the broader questions, Reid plans to unveil the details of his final compromise Wednesday after receiving an official report on its costs and impact. After that, Reid is expected to begin the complex procedural steps required to cut off Republicans’ filibuster, with the first of a series of crucial votes coming as early as Friday.

Without any GOP support, all 60 lawmakers in the Democratic caucus, including two independents, will have to vote for the procedural motions in order for the bill to advance. It will then have to be reconciled with a version passed last month by the House, a stronger bulwark of liberalism than the Senate.

House Democrats welcomed the apparent end of the Senate’s stalemate on the legislation, but were not happy about the drift of its compromises.

“We in the House have made a beautiful souffle, but the Senate has scrambled an egg,” said Rep. George Miller (D-Martinez), noting that Reid already had said he expected to go along with the House in closing the Medicare doughnut hole. “Let’s hope they will find more they like in the House bill.”

Some liberals pledged to vote against the bill if it is in the Senate mold, but Democratic leaders steered clear of such ultimatums. House Majority Leader Steny Hoyer (D-Md.) told reporters that the House could pass the health bill without a public option, contrary to earlier warnings. That was in keeping with advice Democrats say they received long ago from Obama lieutenants like Chief of Staff Rahm Emanuel, who argued that passing any bill would be better than failing to act.

“Rahm told us months ago: Everything can be compromised except our ultimate goal of getting something done,” said Rep. Jim Moran (D-Va.). “Everything else is negotiable.”

And liberals acknowledged they were in a weak bargaining position because conservatives were willing to kill the bill over their disagreements -- and Democrats were not.

“We progressives are negotiating with a gun to our heads,” said Rep. Anthony Weiner (D-N.Y.). “Our opponents are saying, ‘Go ahead and shoot.’ If you’re a public option fan, you haven’t had a good week.”

The final push for Senate action picked up important support today from several leading consumer groups, including AARP, the American Cancer Society Cancer Action Network, Consumers Union and Families USA. The groups plan to join the Service Employees International Union, which has been a leading advocate for a new government insurance plan, at the Capitol on Wednesday to urge senators to quash a Republican-led filibuster next week.

And Health Care for America Now, the influential coalition of liberal activist groups, today decided to send a letter to Reid calling for passage of the legislation, the group’s campaign manager Richard Kirsch said.

“There are major problems with the Senate bill,” Kirsch said in an interview today. “But if the Senate doesn’t act, there will be no healthcare reform. . . . The place to fix [the Senate bill] is in a conference committee” with House and Senate leaders at the table.

The White House meeting came one day after Senate Democrats moved to back down from the idea of expanding Medicare in lieu of the public option, bowing to opposition from conservative Democrats and independent Sen. Joe Lieberman of Connecticut. Democrats were infuriated at Lieberman because he had supported the expansion of Medicare in the past, but the White House tried to defuse that anger.

“If we held flip-flops against everybody in the Congress, we’d probably not have many people there,” Vice President Joe Biden said in an interview on MSNBC’s “Morning Joe” program.

Lieberman joined Obama and Democrats at the White House and signaled that he planned to vote for the bill, according to sources briefed on the meeting. Obama urged others to see the glass as half full, emphasizing that the legislation, like the landmark 1965 law that created Medicare, is a foundation for further improvements in the future.

“Be joyful; be grateful,” Obama said, according to Senate Finance Committee Max Baucus (D-Mont.). “We’ll build upon it in the future.”

In his public comments after the meeting, he said that the emerging Senate bill meets the major criteria he set out in a healthcare speech before a joint session of Congress: It would expand coverage, does not add to the deficit, and slows the rate of growth of healthcare costs.

Beyond that, Obama said, “We simply cannot allow differences over individual elements of this plan to prevent us from meeting our responsibility to solve a long-standing and urgent problem for the American people,” Obama said. “They are waiting for us to act. They are counting on us to show leadership. And I don’t intend to let them down.”

Neither does as staunch a liberal as Sen. Sherrod Brown (D-Ohio), who has steadfastly refused to compromise on including a public option. He said after meeting with Obama that he would vote for the bill despite his reservations.

“There is too much at stake,” he said. “And it’s about me. It’s not about any senator. It’s not about Lieberman.”

noam.levey@latimes.com

janet.hook@latimes.com