It’s become a familiar refrain in Washington by now; President Obama pushes for Republicans to support one of his big initiatives, only to see members of his own party vote against him.

In this April 27, 2010 file photo, Sen. Jon Tester, D-Mont., questions Goldman Sachs chairman and chief executive officer Lloyd Blankfein before the Senate Subcommittee on Investigations on Capitol Hill in Washington.(AP Photo/Charles Dharapak) (Charles Dharapak/AP)

The president, who has for weeks pushed for Congress to “pass this bill” and do so quickly, has also promised that Republicans would pay a political price in the 2012 election for opposing it. And a new Wall Street Journal-NBC News poll suggests he’s right, with 63 percent of Americans saying they support his jobs plan – a new high and a pretty striking number.

But before the poll was released on Wednesday, Democratic Sens. Ben Nelson (Neb.) and Jon Tester (Mont.), who are both up for reelection next year, took to the Senate floor and delivered a sizeable blow to the bill’s prospects by voting against it.

We’ve talked in this space before about how Obama’s political capital has taken a hit as his poll numbers have slid – a reality the president acknowledged in a recent press conference.

“There may be some skepticism that I personally can persuade Republicans to take actions in the interest of the American people, but that’s exactly why I need the American people to try to put some pressure on them,” Obama said last week.

But even before the president’s approval rating dipped toward the 40- percent mark, Obama encountered the same problem.

Moderate and conservative Democrats in both chambers of Congress in red and swing districts and states have yet to vote in lockstep with the president on many or even most of his signature ideas.

Losing a few members of your own party isn’t a death blow by any means. In fact, Nelson has been bucking his party on tough votes for a long time. But by voting the way they did on the jobs bill, the senators also give Republicans political cover to oppose the key legislation.

“It hurts the president a lot,” said a Democratic strategist. “It undermines his efforts. It also diminishes the effect of the legislation and gives the Republicans a pass to vote no.”

As Obama has pushed for Republicans to hear him out on his jobs bill, the response from the GOP has often been to point to the Democrats who are hesitant to do the same.

Even before Wednesday’s defeat — which also included a third Democratic ‘no’ vote from Majority Leader Harry Reid (D-Nev.) for procedural purposes — it was clear that many Democrats in Congress had serious reservations about certain aspects of the legislation. And even as the legislation polls well right now, politicians will always have an eye out for how the bill will be perceived in the future – i.e. the 2012 election.

So it’s no surprise that most of the Democratic resistance to Obama has come from members who could face tough reelection campaigns in 2012. And this is certainly the case with Nelson and Tester.

But if incumbent Democrats in Montana and Nebraska don’t see the bill as a viable vote for their political futures, then it should come as no surprise that neither do many – or possibly any, considering Massachusetts Republican Scott Brown’s ‘no’ vote on the jobs bill – Republicans.

With Nelson’s and Tester’s votes opposition to the bill, Republicans who may have been concerned about its popularity suddenly have an escape hatch. Because if these Democrats think a ‘yes’ vote is a bad move, how could it be smart for a Republican with an even more conservative constituency to support the same legislation?

Democrats insist that the vote Wednesday isn’t a death blow for the jobs bill – and it’s way too early to say whether they’re right.

“It doesn’t help the president, but it’s too politically cute by half,” said a Democratic strategist granted anonymity to discuss the issue candidly. “Democrats in Congress are going to be held just as accountable as Republicans if nothing gets done on jobs.”

Added former Obama adviser Steve Hildebrand: “It doesn’t really hurt (the bill) at all, in my opinion. While they should vote for it because it’s the right thing to do, they voted no because they think it hurts their reelection. So, in my opinion, it hurts them, not Obama.”

Even if that’s the case, the Democratic opposition certainly give the GOP ammunition in fighting back against the jobs plan. And GOP members of Congress will now feel a little safer about voting ‘no” on a bill that is polling quite well.