President Barack Obama's political standing has eroded anew amid setbacks at home and abroad, diminishing public confidence in his leadership, a new NBC News/Wall Street Journal poll has found.
The survey showed that just 41 percent of Americans now approve of Obama's handling of his job, reversing an uptick this spring. The same proportion approve his handling of the economy, while just 37 percent approve his handling of foreign policy—the worst such rating of his presidency.
Read More Obamacare less a negative for president: NBC/WSJ poll
The results come as Obama is beset by violent upheaval in Syria and Iraq, controversy over the prisoner swap that led to the release of Army Sgt. Bowe Bergdahl, and the scandal over poor treatment of injured veterans by the VA health care system. The proportion of Americans who consider the Obama administration "very" or "somewhat competent" has dropped in the past year to 50 percent from 57 percent. Just 42 percent say Obama "can lead the country and get the job done," while 54 percent now say he cannot.
From the public's point of view, "events have controlled Obama rather than Obama controlling events," said Democratic pollster Peter Hart, who conducts the NBC/WSJ survey with Republican counterpart Bill McInturff.
"You've got a lower rating for the president on competence than (President George W.) Bush, post-Katrina," McInturff said. "It's going to be very difficult for him to change his numbers."
Read More
That's bad news for Democratic congressional candidates facing voters this fall, since history shows the president's standing is crucial to his party's performance in mid-term elections. Republicans aim to pad their current majority in the House and gain the six seats they need to recapture control of the Senate.
"It's going to be a very good Republican year," McInturff said. By a 2-to-1 margin, voters who support the tea party movement call themselves more interested in the election than all other voter groups.
In the House, the only saving grace for Democrats is that the number of competitive districts is small enough that even a lopsided defeat is expected to cost them fewer than 10 additional seats. And Democrats generally can take comfort from the fact that, for all Obama's woes, Americans view the Republican Party more negatively than the Democratic Party.
Read MoreHillary has experience to be prez: NBC-WSJ poll
Democrats are viewed positively by 38 percent of Americans and negatively by 40 percent; Republicans are in negative territory by 29 percent-45 percent. Democrats hold a slight 45 percent to 43 percent lead when Americans are asked which party they want to control Congress after this fall's elections.
On key policy choices, there are positive signs for Obama. As he continues to push Congress for an overhaul of immigration laws, a 47 percent plurality says immigration helps the U.S. more than it hurts; 42 percent say it hurts more. A 53 percent majority agree with the administration's arguments in favor of new regulations curbing carbon emissions to stem global warming, outpacing the 39 percent who agree with opponents of the regulations.
Read MoreBenghazi suspect captured
Americans also largely absolve Obama of blame for problems at the VA. Fully 61 percent fault "longstanding government bureaucracy," while just 14 percent point to "poor management by the Obama administration."
At the same time, a 44 percent plurality says Obama should not have traded the release of Bergdahl for five Taliban fighters who had been held at the Guantanamo Bay prison.
The telephone survey of 1,000 adults, conducted June 11-15, carries a margin for error of 3.1 percentage points.
—By CNBC's John Harwood