More than half of Americans for the first time expect Barack Obama to be re-elected - but that won't make it easy: Even as expectations have moved his way, rising gas prices have dented the president's rating on handling the economy, his overall job approval has slipped back under 50 percent and he's reverted to a dead heat in public preferences against Mitt Romney.

The results of the latest ABC News/Washington Post poll mark two political realities: One, the sharp division of public attitudes for and against Obama, with continued greater intensity of sentiment among his critics. And two, the damaging political effects of rising gasoline prices, which have surpassed the federal budget deficit as Obama's single weakest issue.

Americans by a broad 65-26 percent disapprove of how the president is handling the price of gas, which has gained 49 cents a gallon this year to an average $3.79. Strong critics outnumber strong approvers by nearly 4-1. And it's important: A vast 89 percent are concerned about the recent run-up in gas prices; 66 percent are "very" concerned about it.

The survey, produced for ABC by Langer Research Associates, shows a broader impact, underscoring the risk to Obama. His approval rating on handling the economy overall has lost 6 points in a month, to 38 percent, a mere 3 points from his career low in October. Intensity again is highly negative: Fifty percent strongly disapprove of the president's work on the economy, up 9 points to a new high in his presidency.

Challenging as that is for Obama, perceived weakness in his Republican opposition counteracts some of these views. Fifty-four percent of Americans now expect the president to win a second term, up by 8 points from January and by a sharp 17 points from October, before employment gains breathed new life into his then-dim prospects.

Yet the hurdles for Obama remain serious. His support against Romney has pulled back: After a 51-45 percent reading last month, Obama and Romney now stand at 47-49 percent among registered voters. And it's 49-46 percent matching Obama against Rick Santorum. Those mark a scant 4-point gain in support for Romney vs. Obama, and a 5-point gain for Santorum.

GOP - The gap between expectations for Obama in November and his current support is yet more pronounced in comparable results for Romney within his own party. Seventy-four percent of Republicans and Republican-leaning independents expect Romney to be the nominee. But far fewer favor that outcome: Thirty-one percent would like to see him win the nomination, essentially no more than the 29 percent who prefer Santorum. Ron Paul and Newt Gingrich trail with 15 and 14 percent, respectively.

That result marks continuing compunctions about Romney within the GOP ranks. While he leads easily in trust to handle the economy, and especially in views of his electability, he falls short in two other key areas. Leaned Republicans by 31-22 percent trust Santorum over Romney to handle contentious social issues such as abortion and gay marriage, a 12-point gain for Santorum from last month. And Romney only runs evenly with Santorum, 25 to 27 percent, on who best reflects core GOP values.

Differences among groups largely reflect those seen in the Republican primaries to date. Evangelicals prefer Santorum over Romney by a broad 49-19 percent. Santorum leads among those focused on a candidate who shares their religious beliefs, by 39-27 percent, and among very conservatives, by 38 to 21 percent. Romney, in turn, leads among non-evangelicals, matches Santorum among somewhat conservatives and leads among moderates and the few liberals in this population.

While nearly seven in 10 Republicans and Republican leaning independents prefer someone else as the party's nominee, Romney scores reasonably as second choice: Twenty-seven percent of current non-Romney supporters pick him as their No. 2. That's identical to the number of leaned Republicans who name either Santorum or Gingrich as their second preference.

In the end, similar numbers of leaned Republicans say they'd be satisfied with either Romney as their nominee - 66 percent - or Santorum, 69 percent. But that's lower than it might be; in an ABC/Post poll in March 2004, by contrast, 88 percent of leaned Democrats said they'd be satisfied with John Kerry as their nominee.

GAS/ECONOMY - As is fitting after the longest and deepest downturn since the Great Depression, economic attitudes remain the linchpin of the 2012 election. A serious challenge for Obama is that just 31 percent of Americans say his economic policies have made the economy better - his key argument for re-election.

That's moved his way, up sharply from a low of 17 percent in September. But the change has come almost exclusively among Democrats. And as many Americans overall, 30 percent, instead say his policies have made things worse, while 37 percent say they've had no real effect - hardly the sort of economic review Obama wants to bring to the voters in November.

On gasoline, the public is divided on whether prices will go up and stay up, or gyrate up and down. The latter view may be tempering the impact of the increase this time; people who see rising gas prices as an ongoing, cyclical condition are much less apt to see it as a very serious problem, as well as more apt to approve of Obama and to support him for re-election.

Obama's approval, meanwhile, has taken a hit especially among Americans who are less financially secure, and therefore more likely to be affected by higher gas prices: Compared with last month his job rating is down by 17 points among whites with incomes less than $50,000, and by a similar 15 points among non-college-educated whites. His rating drops to 37 percent among people who report financial hardship from gas prices, vs. 60 percent of those who don't.

Even while most Americans criticize Obama's handling of gas prices, the public divides  on whether there's anything he can actually do about it. That's a shift from 2005-06, when six in 10 or more thought the Bush administration could do something to counter the problem.

Despite the impact of gas prices, 66 percent of Americans express optimism about their personal finances in the year ahead, providing Obama with some pushback. However, the public divides evenly in optimism or pessimism about the national economy more broadly. And the latter is more important: As the literature on the subject suggests, optimism about the economy overall significantly predicts intention to vote for Obama; views on personal finances do not.

WOMEN - One recent focus has been the notion of a movement toward the Democratic Party among women, on the basis of recent controversies including the debate over Obama administration policy on insurance coverage of women's birth control.

This poll shows the possibility of Democratic gains among women, but no measurable effect at this point. While women are 12 points more apt than men to identify themselves as Democrats, that essentially matches the long-term norm. Largely because of that partisan gap, Obama's approval rating is 9 points higher among women than men, but again this is typical.

Compared with last month, disapproval of Obama's job performance is up slightly among men, and there's no increase in approval among women. And on vote preference vs. Romney, Obama did better among men and women alike last month, and has lost ground slightly among both sexes this month. In the latest results Romney has a 12-point lead among men who are registered voters; among women, it's Obama +6.

On the latest point of contention, Americans by 61-35 percent say insurance companies should be required to cover the full cost of birth control for women, including majorities of women and men alike (65 and 57 percent, respectively). (Young people, in particular, favor such coverage.) If the insurance is provided through a religiously affiliated employer that objects to birth control, however, support for this requirement drops to 49 percent (52 percent of women, 45 percent of men).

More generally, Democrats have a broad 25-point margin over the Republicans as the party that's more in tune with women's issues, 55 percent to 30 percent - a view held essentially equally by men and women alike. But again the recent jousting may not have changed much, since if anything this view was even more broadly held, by 58-24 percent, in an ABC/Post poll a dozen years ago.

Beyond its advantage on women's issues, the Democratic Party has a 10-point lead in being seen as "more concerned with the needs of people like you" and a scant 5-point edge as the party that "better represents your own personal values." As befits their partisan preferences, women are more likely than men to pick the Democrats, by 9 points on values and by 7 points on empathy.

While these are essentially unchanged since last measured in 2010, there's one group worth noting: Women who are political independents. They've shifted from an 11-point margin in favor of the GOP as better representing their personal values in September 2010 to a narrow +5 margin for the Democratic Party now. They've also moved away from the GOP, albeit more slightly, on which party is more concerned with their needs, from +8 GOP to +2 Democrats. While other shifts counteracted these in overall results, the finding suggests that independent women will be a group to watch as the campaign progresses.

METHODOLOGY - This ABC News/Washington Post poll was conducted by telephone March 7-10, 2012, among a random national sample of 1,003 adults, including landline and cell-phone-only respondents. Results have a margin of sampling error of 4.0 points for the full sample. The survey was produced for ABC News by Langer Research Associates of New York, N.Y., with sampling, data collection and tabulation by Abt-SRBI of New York, N.Y.