The public opinion boost President Obama received after the killing of Osama bin Laden has dissipated, and Americans’ disapproval of how he is handling the nation’s economy and the deficit has reached new highs, according to a new Washington Post-ABC News poll.

The survey portrays a broadly pessimistic mood in the country this spring as higher gasoline prices, sliding home values and a disappointing employment picture have raised fresh concerns about the pace of the economic recovery.

By 2 to 1, Americans say the country is pretty seriously on the wrong track, and nine in 10 continue to rate the economy in negative terms. Nearly six in 10 say the economy has not started to recover, regardless of what official statistics may say, and most of those who say it has improved rate the recovery as weak.

New Post-ABC numbers show Obama leading five of six potential Republican presidential rivals tested in the poll. But he is in a dead heat with former Massachusetts governor Mitt Romney, who formally announced his 2012 candidacy last week, making jobs and the economy the central issues in his campaign.

Among all Americans, Obama and Romney are knotted at 47 percent each, and among registered voters, the former governor is numerically ahead, 49 percent to 46 percent.

Overall, about six in 10 of those surveyed give Obama negative marks on the economy and the deficit. Significantly, nearly half strongly disapprove of his performance in these two crucial areas. Nearly two-thirds of political independents disapprove of the president’s handling of the economy, including — for the first time — a slim majority who do so strongly.

In another indicator of rapidly shifting views on economic issues, 45 percent trust congressional Republicans over the president when it comes to dealing with the economy, an 11-point improvement for the GOP since March. Still, nearly as many, 42 percent, side with Obama on this issue.

The president has sought to point to progress on the economy, particularly in the automobile industry, and to argue that the policies he put in place at the beginning of his term are working. But the combined effects of weak economic indicators and dissatisfaction among the public are adding to the political pressures on the White House as the president’s advisers look toward what could be a difficult 2012 reelection campaign.

Meanwhile, Romney emerges in the new survey as the strongest current or prospective Republican candidate in the 2012 presidential field. Although he is by no means in a secure spot, on virtually every measure, the former governor appears better positioned than any of his rivals.

In contrast, the poll brings more bad news for former Alaska governor Sarah Palin, whose bus tour along the East Coast last week renewed speculation that she might join the race.

Almost two-thirds of all Americans say they “definitely would not” vote for Palin for president. She is predictably unpopular with Democrats and most independents, but the new survey underscores the hurdles she would face if she became a candidate: 42 percent of Republicans say they’ve ruled out supporting her candidacy.

More than six in 10 Americans say they do not consider Palin qualified to serve as president. That is a slightly better rating for the former governor than through most of last year, but is another indication of widespread public doubts about a possible presidential run.

The Post-ABC poll asked Republicans and GOP-leaning independents whom they would vote for if a primary or caucus were held now in their state. Romney topped the list, with 21 percent, followed by Palin at 17 percent. No one else reached double digits, although former New York mayor Rudolph W. Giuliani, who has suddenly shown interest in becoming a candidate, is close, at 8 percent. Without Palin in the race, Romney scores 25 percent, with all others in the single digits.

In another measure of the field, Republicans chose Romney as the only one of a dozen possible candidates they would “strongly consider” for the party’s nomination as opposed to stating that they definitely would not vote for him. He and Palin scored equal numbers of respondents who said they would strongly consider supporting them, but Palin has more than double the percentage who have ruled her out.

Other candidates fared poorly on this count, including former House speaker Newt Gingrich (Ga.), whose campaign got off to a rocky start; Rep. Ron Paul (Tex.), a libertarian who has a passionate following but many detractors; and former senator Rick Santorum (Pa.), who announced his candidacy on Monday.

The Massachusetts health-care plan enacted under Romney remains a potentially serious problem in the former governor’s bid. By nearly 2 to 1, Republicans oppose the plan, with strong detractors far outnumbering solid supporters. But there is some potential for him to frame the matter: Almost four in 10 Republicans expressed no opinion about the state’s program.

Overall dissatisfaction with the GOP field remains high, with as many respondents saying they are unhappy with their choices as say they are satisfied. At this time four years ago, nearly seven in 10 Republicans said they were satisfied with their field of candidates.

In head-to-head matchups with Obama, Palin trails by 17 percentage points, the worst of the six possible candidates tested. The president leads Gingrich and former Utah governor Jon Huntsman Jr. by 10 points. He runs 11 points ahead of former Minnesota governor Tim Pawlenty and 13 points ahead of Rep. Michele Bachmann (Minn.).

Romney owes his relatively good standing against the president to support from independents. He and Obama garner roughly equal percentages from those in their own parties. But independents split for Romney 50 percent to 43 percent.

The president continues to receive positive marks as a strong leader, but the 55 percent rating marks a low point of his presidency. He gets mixed reviews on empathy and on sharing the same values as respondents.

The telephone poll was conducted June 2-5 among a random national sample of 1,002 adults. The results from the full survey have a margin of sampling error of plus or minus 3.5 percentage points.

Polling manager Peyton M. Craighill and polling analyst Scott Clement contributed to this report.