Obamacare, shutdown hurt Obama's standing: NBC News/WSJ poll

President Barack Obama
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The troubled rollout of the new health-care law and recent government shutdown have exacted a major toll on President Barack Obama's standing, a new NBC News/Wall Street Journal poll has found.

Obama's job approval rating has tumbled by 5 percentage points in less than three weeks, the survey showed. In the weakest showing of his five-year tenure, just 42 percent of Americans approve of the president's job performance, while 51 disapprove.

The poll underscores the fact that Obama and his GOP adversaries have been hit by what NBC/WSJ pollster Bill McInturff called a public opinion "shock wave" this fall. Obama's personal favorability declined to the weakest point of his presidency—41 percent positive, 45 percent negative. And pluralities of 38 percent and 41 percent said the shutdown made them feel less favorably about Democrats in Congress and Obama, respectively.

Peter Hart, the Democratic pollster who conducts the survey with Republican McInturff, also pointed to Obama's uncertain handling of the conflict in Syria and controversy over National Security Agency surveillance. "Personally and politically," Hart concluded of the president's standing, "the public assessment is two thumbs down."

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Republicans in Congress continued to face fallout of their own, with 53 percent of poll respondents saying the recent government shutdown made them feel less favorably toward GOP lawmakers on Capitol Hill. The Republican Party received its weakest favorability rating in the quarter-century history of the NBC/WSJ poll, with just 22 percent expressing positive views and 53 negative views.

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Across the board, Hart concluded, "these events have sapped the American spirit." Fully 70 percent of Americans called the nation "off on the wrong track," compared with just 22 percent who say it is "headed in the right direction."

Obama's challenges with the health-care law have compounded the damage. By 40 percent to 9 percent, Americans said recent news has made them less confident about the law rather than more confident. While just 24 percent say the law should be "totally eliminated"—a core Republican demand—28 percent say it needs "a major overhaul."

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On the problem-plagued federal health-care exchange website, 31 percent say they think troubles stem from a long-term design flaw that can't be corrected. Some 37 percent say they think it can be corrected, while 30 percent consider it too soon to tell.

The broader decline in confidence appears more worrisome to the White House and Congress alike. A 63 percent majority considers American "in a state of decline"—up 9 percent since January 2011.Seventy-four percent said Congress is contributing to problems rather than solving them.

If there's any consolation for the White House and congressional incumbents facing re-election next year, it's a slight easing of pessimism about the economy. The proportion of Americans expecting the economy to worsen in the next year has declined to 34 percent from 42 percent earlier this month. The proportion expecting the economy to improve ticked up to 23 percent from 17 percent.

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Democrats can look toward the 2014 mid-term elections with some reason for hope. By 45 percent to 41 percent, respondents said they want Democrats rather than Republicans to control Congress after next year's balloting.

But Republicans can take heart from the robust standing of New Jersey Gov. Chris Christie, a potential 2016 presidential candidate. Christie was rating positively by 33 percent of Americans, and negatively by just 17 percent. The potential Republican candidate who helped point the party toward the shutdown—Sen. Ted Cruz of Texas—was rated positively by just 19 percent, negatively by 30 percent.

Potential Democratic candidate Hillary Clinton, for her part, joined Christie in positive territory. Some 46 percent expressed favorable views about her, while 33 percent voiced negative views.

The telephone survey of 800 adults, conducted Oct. 25-28, carries a margin for error of 3.46 percentage points.

—By CNBC's John Harwood. Follow him on Twitter: @JohnJHarwood.