Maybe this is premature. But it’s hard to avoid a sense that there’s a major shift underway on the debt ceiling — one that is going to leave the hard-core anti-debt-limit-hike dead enders more marginalized than ever.

First, a new NBC/WSJ poll has just come out finding that a majority of Americans, 55 percent, now believe not raising the debt ceiling would be a real and serious problem. That includes 59 percent of independents and 47 percent of Republicans. This suggests a real swing in opinion; previous polls have found that large numbers of Americans don’t see failure to raise it as a serious risk.

This comes after a new Gallup poll finding that an astonishing 57 percent of Republicans want their leaders to reach a debt limit compromise even if they disagree with it.

Second, a bipartisan group of Senators — the Gang of Six — released a new deficit reduction plan that combined revenue increases with spending cuts and and overhaul of entitlements. This plan is probably a nonstarter on both sides — if it cuts entitlements benefits then Dems should oppose it. But at an impromptu press briefing just now, Obama immediately grabbed on to the plan to claim momentum for his approach, which balances revenue increases and spending cuts.

“The framework that they’ve put forward is broadly consistent with what we’ve been working on here in the White House,” Obama said. “We have a Democratic President and administration that is prepared to sign a tough package that includes both spending cuts, modifications to Social Security, Medicaid and Medicare that would strengthen those systems and allow them to move forward — and would include a revenue component. We now have a bipartisan group of Senators who agree with that balanced approach. And we’ve got the American people who agree with that balanced approach.”

That last sentence is borne out by five national polls that Steve Benen has illustrated in useful graph form.

Third, in the press briefing, Obama went further than ever before in endorsing the Mitch McConnell proposal as a last resort. “That continues to be a necessary approach to put forward in the event that we don’t get an agreement,” Obama said. “At minimum, we’ve got to raise the debt ceiling.”

On a separate note, a new Washington Post poll finds that the President holds a clear advantage over Congressional Republicans on who is protecting the economic interests of the middle class and edges the GOP on who is helping small businesses.

This is Washington, so the only certainty is that anything can happen. And no illusions: Whatever final deal does emerge is likely to be skewed badly in the direction of spending cuts or may well cut entitlements benefits in a way that’s unacceptable to liberals. At a minimum the McConnell proposal would ensure that the crosshairs of another “commission” will be on entitlements next year. There’s no denying that overall, the discussion has moved way further to the right than we’d like.

But right now, it seems clear that the ground in the debt ceiling standoff is shifting decisively towards Dems, and it’s increasingly obvious that the White House is firmly in control of the debate.