An American soldier prepares to board a helicopter at an observation post in Paktika Province, Afghanistan. More than three in four Americans say they support the withdrawal of U.S. troops from Afghanistan, according to a new Washington Post-ABC News poll. (Kevin Sieff/WASHINGTON POST)

President Obama has widespread support for his decision to withdraw U.S. forces from Afghanistan by the end of 2016, but a scandal at the Department of Veterans Affairs has united the country in its alarm about the problems, according to a new Washington Post-ABC News poll.

Overall, 46 percent of Americans approve of the job Obama is doing as president, up from 41 percent in late April. Fifty-one percent say they disapprove. The 46 percent matches his approval ratings in late January and early March, which could mean the April finding was an anomaly. The major difference between now and the last survey is that a higher percentage of Democrats say they approve of his performance.

Obama’s Afghanistan announcement drew some criticism last week from Republican lawmakers, but more than three in four Americans say they back the timetable for withdrawal. Solid majorities of Democrats, Republicans and independents support the decision, although Republicans are significantly less enthusiastic.

The VA scandal, in contrast, shows no partisan differences and reflects public outrage over reports of long delays for treatment and falsification of records at some veterans’ facilities. The new poll finds a near-unanimous verdict, with 97 percent of Americans describing the problems as serious and 82 percent calling them “very serious.”

The White House has scrambled to get on top of the situation and the public appears to put the responsibility for the problems elsewhere than on Obama. About four in 10 Americans say the president deserves significant blame for the problems that have mushroomed into a major debacle for his administration, while six in 10 say he deserves just some or none.

View Graphic President Obama’s Afghanistan plan is popular

Partisan differences color the apportionment of responsibility. About six in 10 Republicans say Obama was principally to blame, while three in five independents and four in five Democrats say most of the blame should be placed elsewhere.

On Friday, Obama said he had accepted the resignation of VA Secretary Eric K. Shinseki as a succession of Democratic senators facing reelection, and others, demanded that the retired general resign or be fired. The public strongly supports that move, with 65 percent saying that it was right for Shinseki to step down.

The poll finds overwhelming support for the administration’s initiative to combat climate change by reducing carbon dioxide emissions at existing coal plants. On Monday, the Environmental Protection Agency proposed a regulation aimed at cutting those emissions by up to 30 percent by 2030 and giving states options for trying to meet the targets.

Nearly seven in 10 Americans say they regard climate change as a serious problem, with big majorities among Democrats and independents agreeing and Republicans evenly split on their assessments. Seven in 10 also support government efforts to require limits on emissions from existing power plants. More than six in 10 say they would support the plan even if it meant paying an extra $20 a month on their electric bills.

With the House preparing for hearings by a new select committee investigating the 2012 attacks on a U.S. diplomatic outpost in Benghazi, Libya, the poll found public doubts about the administration’s credibility. Almost six in 10 say the administration has tried to cover up the facts of what happened, which is about the same percentage who said so a year ago.

A bare majority (51 percent) say they support another congressional inquiry, with 42 percent saying the issue has been investigated enough. Half say they disapprove of how then-Secretary of State Hillary Rodham Clinton handled the incident, with 37 percent approving.

On a series of specific issues, Obama’s approval ratings are a net negative. Just 38 percent of Americans approve of his handling of immigration reform, 39 percent approve of how he has handled the implementation of the new health-care law, 41 percent approve of his overall handling of international issues and 43 percent approve of his handling of the economy. At least 50 percent disapprove of his handling of those four areas.

Secretary Eric Shinseki has stepped down as head of the Department of Veterans Affairs. Here’s a breakdown of what’s happened, since the alleged misconduct at the veterans hospital in Phoenix. (Pamela Kirkland/The Washington Post)

On Afghanistan, despite the overwhelming support for his troop-withdrawal plan, the public is evenly divided over his performance, with 45 percent approving and 45 percent disapproving.

There are wide partisan differences in assessments of Obama’s handling of all these issues.

Interest in the November midterm elections has grown in the past month, with 74 percent of registered voters saying they are certain they will vote, up from 68 percent in April. Slightly more Republicans than Democrats and more whites than nonwhites say they definitely will vote. Democrats are particularly worried about low turnout by their coalition in November.

Registered voters are split almost evenly in their preference for House elections. Forty-seven percent say they would vote for the Democratic candidate while 45 percent say they would vote for the Republican. Historically, Democrats have needed a significantly larger margin on this question to avoid losses.

The economy continues to top the list of issues that will affect voters. A quarter of all registered voters cite the economy as one of the most important issues. Next in importance is the way Washington is working (19 percent), followed by the federal deficit and the Affordable Care Act (18 percent and 16 percent, respectively).

Climate change, immigration and same-sex marriage were in the single digits when voters were asked whether the issues were among the most important in determining their vote.

Democrats are hoping to energize female voters by focusing on a number of women’s issues. The poll found that, overall, just 8 percent of registered voters highlighted those as one of their most important issues — 12 percent of women and 2 percent of men.

The public expresses slightly greater confidence in Obama to deal with the country’s main problems over the next few years than in congressional Republicans, 43 percent for Obama to 38 percent for the GOP. The president comes out better on this than he did at the end of last year, but the five-point margin is only one-third as large as it was in December 2012 after the his reelection.

The Post-ABC poll was conducted May 29 to June 1 among a random national sample of 1,002 adults, including users of conventional and cellular phones. Results from the full survey have a margin of error of plus or minus 3.5 percentage points.

Peyton M. Craighill contributed to this report.