Mitt Romney heads into his nominating convention with a solid shot at the presidency but substantial challenges en route - including broad perceptions among a downturn-battered public that, if elected, he'd favor wealthy Americans over the middle class.

That view complicates Romney's job winning over the economically distressed white voters among whom his fortunes may depend. It's also expressed in his persistent weakness in personal popularity overall, as well as his shortfall against Barack Obama in views he understands the economic problems ordinary Americans are having.

See PDF with full results, charts and tables here.

Registered voters by a substantial 58-32 percent in the latest ABC News/Washington Post poll think Romney would do more to favor the wealthy than the middle class - the opposite of views on Obama's priority. Obama has a slight 7-point edge in better understanding the public's economic straits, and another wide lead, 61-27 percent, as seeming more friendly and likeable.

As he seeks to address those weaknesses, Romney grasps his party's presidential nomination with pushback on at least two fronts: Better alignment with public preferences for more limited government, and steady dissatisfaction with Obama's economic performance. Fifty-six percent of registered voters disapprove of Obama's work on the economy; largely as a result, fewer than half, 47 percent, approve of his job performance overall.

These competing sentiments boil down to essentially a dead heat in vote preferences. Among registered voters in this national survey, 47 percent support Romney, while 46 percent favor Obama, a split well within the margin of sampling error.

It's the seventh time in 14 ABC/Post surveys this cycle that Romney's held a scant (even 1-point) numerical edge. That marks his continued opportunity, but also his difficulties taking full advantage of Obama's weaknesses, particularly on the still-struggling economy. Eighty-five percent of registered voters say it's in bad shape, and, in a related result, seven in 10 say the country's seriously off on the wrong track - two highly hazardous numbers for incumbents.

Indeed, Obama's support has slipped numerically in each of the last four ABC/Post polls - from 51 percent in April to 46 percent now - as economic sentiment has worsened amid persistent unemployment and a resumption in rising gasoline prices.

Romney, crucially, has a slight, seven-point lead among registered voters in trust to handle the economy, 50-43 percent. And he benefits from the fact that 58 percent say they're not confident the economy would improve under a second Obama term. But 52 percent aren't confident it would improve under Romney, either - suggesting that beyond criticizing Obama's economic performance, Romney could benefit by sharpening his argument that he'd do better.

Among other results, this survey, produced for ABC by Langer Research Associates, finds a weak reception for Paul Ryan as Romney's vice presidential running mate - 54 percent of registered voters approve of the choice, somewhat lower than the customary levels in past elections. Still, that rises to 85 percent of "very" conservative registered voters and as many of those who strongly favor the Tea Party political movement, good for Romney in the GOP base.

Overall, though, two-thirds of registered voters say Ryan's selection will make no difference in their vote, while the rest divide essentially evenly on whether it makes them more or less likely to back the GOP ticket. And there is a risk: Registered voters by a broad 62-33 percent oppose Ryan's proposal to restructure Medicare. To date that does not look to have impacted trust to handle the issue, about an even division between Obama and Romney. That's in fact a plus for Romney, given the traditional Democratic advantage on Medicare. The question is how it plays out in the campaign ahead.

It's been tough so far for either candidate to gain much resonance. Apart from two polls with slight advantages for Obama in February and April, he and Romney have been essentially tied in 12 other ABC/Post matchups since April 2011. And while they're basically even in trust to handle one issue on which Obama has opportunity, Medicare, they're also tied on another, assisting small business, on which Romney's sought to portray Obama as out of touch.

The two are essentially even in trust to handle several other contentious issues, as well, including health care policy and education. Romney prevails in trust to handle the federal deficit. But Obama holds a big advantage, 52-38 percent, in trust to handle "social issues such as abortion and gay marriage," and leads Romney by 16 points on "addressing women's issues." (Neither of those has changed since spring.)

By extension of views on women's rights, Romney's overall support from registered women voters, a persistent difficulty for him, is just 43 percent, compared with his 51 percent support among men. (Obama, by contrast, has 49 percent support from registered women voters, 42 percent from men.)

Atop all these issues, the weight of public expectations represents another hurdle for Romney to address. Despite the dead-heat horse race, and the economy's continued straits, 56 percent of registered voters say they expect Obama ultimately to win a second term.

GOVERNMENT and POLICY - As noted, stated preferences on the size of government favor Romney. Fifty-nine percent of registered voters say they prefer smaller government with fewer services over larger government with more services. Sixty-nine percent ascribe the same preference to Romney. But 73 percent think Obama, instead, prefers larger government.

That result presents Romney with an unquestioned opportunity to pin the "big government" tag on Obama. But there are limits to the approach, and responses available to the Democratic camp.

For one, even while they profess a preference for smaller government, registered voters by 51-37 percent also say they think the government would do better trying to create jobs by "spending money on projects like roads, bridges and technology development" rather than by cutting taxes - an argument more in tune with Obama's position than Romney's. It matters: While those who prefer cutting taxes favor Romney by a vast 69-24 percent, those who see government spending as a better jobs-maker favor Obama by 62-31 percent.

Views of fairness - an Obama theme - also represent a potential shoal for Romney. Registered voters by an 18-point margin, 54-36 percent, see "unfairness in the economic system that favors the wealthy" as a bigger problem than "over-regulation of the free market that interferes with growth and prosperity," again showing more alignment with the Democratic argument. And again the connection with vote preference is profound - 87-11 percent for Romney among those focused on over-regulation; 71-20 percent for Obama among those concerned with fairness.

Beyond these, the Obama campaign may be seeking to keep a focus on Romney's personal wealth - and by extension the sense he'd favor the wealthy over the middle class - by continuing to call for fuller release of his tax returns.

Registered voters divide exactly evenly on whether or not fuller tax disclosure by Romney is needed, but just two in 10 call the issue a major factor in their vote. (That rises sharply among Obama supporters, likely the reason his campaign keeps on it.) Seventy-two percent, by contrast, call Obama's handling of the economy a major factor.

Again, though, Obama can find a reply: By 52-34 percent, more continue to blame the economy's current condition not on Obama, but on his predecessor, George W. Bush.

GROUPS and MOVERS - At 47-46 percent, Romney-Obama, vote preferences among registered voters now show a difference compared with all adults, who divide 49-42 percent in Obama's favor, a result indicating the pressure on Obama's side to register and turn out its base. (Among likely voters, at 49-47 percent, Romney-Obama, the race is similar to its level among registered voters.)

There's room to move: More than half of Romney's and Obama's supporters alike are less than "very" enthusiastic about their candidate. Fifteen percent say there's a chance they may change their minds, plenty enough to shake up the contest. Moreover, majorities say they're anxious about how their preferred candidate would perform in office (53 percent in Obama's case, and more, 62 percent, in Romney's), and four in 10 say they're seeking more information about the candidates - two more subtle indicators of the potential for movement.

Preferences - on policies and between candidates alike - of course are associated with partisan and ideological affiliation. Obama leads by 84-14 percent among liberals, while Romney holds numerically his best advantage to date among conservatives, 77-16 percent (though it was very similar in March). There are easily more conservatives than liberals among registered voters; Obama makes it back among moderates.

Independents, who often have been swing voters in national elections, divide narrowly, 47-43 percent between Romney and Obama among registered voters - a bit softer for Romney than last month. Obama's helped by the fact that Democrats outnumber Republicans by 7 points among registered voters in this survey (as they did in the 2008 exit poll). At the same time, his 83 percent support among Democrats lags Romney's 91 percent among Republicans.

Among other groups, Romney holds a broad 55-37 percent advantage among whites overall, while Obama has 76 percent support from nonwhites. As noted, economically stressed whites may be of particular interest; among those with incomes under $50,000, Romney has 50 percent support in this group - indicating opportunity to improve, if he strikes the right message.

TONE and REACHOUT - Another potential factor is the campaign's tone, an issue on which there are criticisms on both sides: More than half of registered voters say each candidate has been mainly attacking his opponent rather than addressing the issues.

Slightly more say that about Romney than said it about John McCain at about this time in 2008. But vastly more say it about Obama now - 56 percent - than did in late August 2008, just 29 percent. The question here is whether that change in tone draws more voters to a more-combative candidate Obama - or sends them away.

A final issue, and a potentially critical one, is voter contact - and on this measure, Obama has the high ground. As of this point, relatively few of Romney's supporters, 18 percent, say they've been contacted by a representative of his campaign. Far more Obama supporters - 31 percent - say they've been contacted by Obama's campaign. The ground game is one key battle Obama won four years ago. For Romney, once his convention's over, it's another important box to check.

METHODOLOGY - This ABC News/Washington Post poll was conducted by telephone Aug. 22-25, 2012, among a random national sample of 857 registered voters (out of 1,002 adults overall), including landline and cell-phone-only respondents. Results have a margin of sampling error of 4 points for the full sample and registered voters alike. 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.