WASHINGTON – President Obama’s $447 billion jobs plan foundered Tuesday night in the Senate as a unified Republican caucus and a pair of Democrats joined to deny the proposal the 60 votes necessary to allow it to proceed to full consideration.

The president continued to travel around the country promoting the plan, speaking Tuesday at a union training center in Pittsburgh.

Obama will now use Republican opposition as part of a campaign to paint the GOP as obstructionists blocking his efforts to improve the economy while offering no alternative to create jobs.

Although a number of Democrats who will face tough re-election efforts next year had wavered in support, only two voted not to allow the measure to advance, a symbolic victory for Obama and Senate Democratic leaders, who knew that strong Democratic opposition would be an embarrassment for the White House.

“The president’s plan contains many ideas Republicans have consistently supported over the years, especially when their party controlled Congress, the White House or both,” said Senate Majority Leader Harry Reid, D-Nev. “Republicans oppose those ideas now. … I guess Republicans think if the economy improves, it might help President Obama.”

Senior White House officials said the vote was the first step to spur action on job creation. Next, they said, Obama will work with Senate leaders to break the jobs bill down into its parts, which polls show are very popular with voters, and challenge Republicans to reject each individually.

They think Republicans will find it hard to deny the extension of a break on payroll taxes for workers, worth about $1,000 a year to the average family.

“This will just be the first act in a long-term play here over the next couple of months,” a senior White House official said hours before Tuesday night’s vote. “Either one, we get a lot of this done and it’s good for the economy, which is our preference. Or we don’t, and the American people know why.”

A senior Senate Democratic aide confirmed that Sen. Charles Schumer, D-N.Y., has been shopping a plan to package the creation of an infrastructure bank to fund transportation improvements, an element of Obama’s jobs bill, with a proposal favored by many Republicans to offer corporations a tax break if they return offshore earnings to the United States.

GOP Sens. Susan Collins and Olympia Snowe of Maine joined other Republicans in voting no, but both said there are a number of job-creating elements in the package that are worth support.

“Job creation is indisputably our nation”s number one priority, and there are elements of the president”s package that Republicans and Democrats should be able to agree upon,” Snowe said in a statement after the vote. “Unfortunately, yet again the Senate was faced with a take it or leave it package to which no amendments would be allowed on this bill with massive and wide-ranging implications.”

Collins also charged that Republicans were faced with a “take or leave it proposition.”

Republicans said they have always preferred negotiating the package piece by piece, and said the vote was an effort to turn the debate into a political bludgeon.

Collins said in a statement that, “The bill considered today has some elements that could garner overwhelming bipartisan support such as a payroll tax deduction for employees and employers. It would also provide tax incentives to encourage the hiring of our veterans, another good idea. We should consider and pass these and other proposals on which there is agreement.”

Republicans note that both chambers will vote this week on new free-trade agreements with Colombia, Panama and South Korea, deals supported by both parties and advocated by Obama for months.

Later this week, the House will also weigh a proposal to provide new training dollars for veterans entering the work force, similar to a piece of Obama’s plan that would provide tax credits for businesses that hire veterans.

“This whole exercise, by their own admission, is a charade that’s meant to give Democrats a political edge in an election that is 13 months away,” Senate Minority Leader Mitch McConnell, R-Ky., said of the vote on the package.

Obama has barnstormed the country to encourage a congressional vote on the American Jobs Act as a whole. He went Tuesday to a union training center in Pittsburgh, where he called the vote a “moment of truth” for the Senate.

Besides payroll tax cuts for workers and small businesses, the package includes tax credits for businesses that hire veterans and the long-term unemployed, funds for road and school construction, and dollars for hiring teachers and first responders.

“Today’s the day when every American will find out exactly where their senator stands on this jobs bill,” Obama said in Pittsburgh. “Any senator who votes no will have to look you in the eye and tell you what exactly they are opposed to.”

But Republicans will argue that the Senate defeat shows Obama’s ability to harness the bully pulpit to compel legislative action has waned as his popularity has fallen.

Democratic Sens. Ben Nelson of Nebraska and Jon Tester of Montana, who each face tough re-election bids in conservative states, voted against the bill. Retiring Sen. James Webb, a Democrat from the key swing state of Virginia, and Sen. Joe Manchin, D-W.Va., voted to let the bill advance but said they were opposed to it without changes.

The vote was 50-48 early in the evening, but was held open to allow for a late-arriving Jeanne Shaheen, D-N.H., to cast a vote. She voted yes, making the final tally 51-48.

Republicans remained unified against the package even after Democrats tried to make the vote a choice between workers and the wealthy. They swapped Obama’s suggestion that the package be funded by tax hikes on those making more than $250,000 for a 5.6 percent tax on millionaires.

In so doing, Senate leaders tried to tap into widespread public discontent over the growing income gap between rich and poor, frustrations that have given rise to weeks of protests in New York, Washington and elsewhere.

Those protests arrived at the Capitol on Tuesday, as a group affiliated with the “Occupy D.C.” movement unfurled banners in the Senate’s Hart Office Building calling for an end to overseas wars and for increased taxes on the rich. Six were arrested.