Sen. Ben Nelson (D-NE) waits for an elevator outside the Senate floor after voting against President Barak Obama's America Jobs Act. (Chip Somodevilla/GETTY IMAGES)

Not long before the Senate voted to block his $447 billion jobs package on Tuesday, President Obama described the impending roll call as a “moment of truth.”

He meant for Republicans, whom he blames for quashing his attempts to improve the economy and who voted as a bloc against the plan.

But he could also have been talking about those moderate Democrats who face reelection fights next year, and who will be deciding in the coming months how closely to ally themselves to a president who is sinking in the polls.

After some public wavering by several of those Democrats, only two bucked the president and voted against the measure — Sens. Jon Tester (Mont.) and Ben Nelson (Neb.).

The defections allowed Republicans to label opposition to the president “bipartisan,” but the small number let Democrats claim that their caucus stood behind the president.

Democratic leaders had fought hard to get 51 of their members on board so they could show that the bill could pass, if Republicans had not required that it clear the 60-vote hurdle that has become the standard for any action in the gridlocked Senate.

“We worked real hard to get a majority, which we did. And it shows that Republicans are blocking jobs,” said Sen. Charles E. Schumer (D-N.Y.) at a breakfast meeting Wednesday.

At the same time, moderate Democratic Sens. Joe Manchin (W.Va.) and James Webb (Va.), along with independent Sen. Joseph I. Lieberman (Conn.), who caucuses with the Democrats, each indicated that they opposed the bill and voted to break the filibuster only so it could receive further debate.

“The president is becoming less and less popular,” said Sen. John Cornyn (Tex.), chairman of the National Republican Senatorial Committee. “And as his policies have become less and less popular, we’re seeing fewer and fewer Democrats willing to stake their political survival on his record.”

In an interview, Tester denied that his vote against the package had to do with Obama or his own tough reelection campaign. “Because we are a highly public race, everything we do, people will analyze from an election standpoint. That’s not how I look at it at all,” he said in an interview. “Good policy makes good politics. I didn’t think this was particularly good policy.”

Tester said that he supports some elements of the president’s plan, including offering tax credits to businesses that hire veterans and boosting federal spending for infrastructure construction, and that he could vote for those pieces of the plan if they were presented separately for consideration.

But he said that a proposal to extend a payroll tax holiday for workers and expand it to include payroll taxes paid by some employers was a bad way to spur economic growth.

Like Tester, Nelson is considered particularly vulnerable by Republicans as they seek to pick up the four seats they need to gain control of the Senate.

One of the Senate’s most conservative Democrats, Nelson has worked especially hard to show his independence from the party.

In a statement, he rejected the jobs package’s underlying premise, indicating that he could not support the bill because it includes billions in higher spending and tax increases.

“I simply can’t support raising taxes so Washington can spend more,” he said.

Other Democratic senators who also face tough reelection races backed the plan.

Sen. Claire McCaskill (Mo.), who raised eyebrows when she did not join Obama at a St. Louis event earlier this month, voted to move the bill forward. “This plan won’t solve all of our economic problems, but it would be a step in the right direction,” she said in a statement.

Also voting yes were Sens. Sherrod Brown (Ohio), Debbie Stabenow (Mich.) and Robert P. Casey Jr. (Pa.). Each of them faced a GOP television campaign urging them to vote against the package, as well as a 5.6 percent surtax on millionaires that Democrats have proposed to pay for it.  

At a Wednesday luncheon, Senate Democrats weighed which piece of the president’s plan to put forward for a vote next. Leaders indicated that they may consider appropriations measures next week and return to the jobs proposals the first week of November, after a scheduled week-long recess at the end of this month.