Charles Dharapak/AP Photo

Mitt Romney has seized further advantage on economic issues at the core of the 2012 campaign, taking him to 50 percent support among likely voters vs. 47 percent for Barack Obama - Romney's highest vote-preference result of the contest to date.

The difference between the two candidates is within the margin of sampling error in the latest ABC News/Washington Post daily tracking poll, and their individual support levels have not significantly changed. But the momentum on underlying issues and attributes is Romney's.

See PDF with full results and charts here.

Romney's gains are clear especially in results on the economy. This poll, produced for ABC by Langer Research Associates, finds that likely voters now pick Romney over Obama in trust to handle the economy by 52-43 percent - the first time either candidate has held a clear lead over the other on this central issue.

Equally important, Romney has erased Obama's customary advantage on which candidate better understands the economic problems of average Americans. Today, 48 percent pick Obama, 46 percent Romney - essentially a dead heat. Yesterday and today mark the first time in the campaign that Obama hasn't had at least a marginally significant lead on economic empathy.

Within-group trends on both these economic measures were covered in yesterday's analysis; they reflect movement in Romney's direction almost exclusively among white men, and particularly among less-educated white men.

SIGNALS - There are other signals of Romney's gains. Expectations are one: Fifty-two percent of likely voters now expect Obama to win the election, down from a peak of 61 percent in late September. Forty percent expect Romney to win - still well fewer than half, but up by 8 percentage points.

Notably, political independents divide by 42-46 percent on whether they expect Obama or Romney to win; that's shifted dramatically from 61-31 percent in Obama's favor. Whites, likewise, have moved from a 55-38 percent expectation in Obama's favor Sept. 29 to 44-48 percent now.

Romney is more competitive in another area, as well - international affairs. Even though likely voters by 2-1 picked Obama as the winner of Monday's debate on foreign policy, comfort with Romney on the issue nonetheless has progressed. He runs essentially evenly with Obama in trust to handle international affairs, 48-47 percent, Obama-Romney; they were about this close on Monday, but it was +7 for Obama in mid-October and +8 in early September.

Obama retains a larger numerical (but not significant) edge on another issue, trust to better advance the interests of the middle class, 50-45 percent. It was similar, 51-43 percent, when last asked in an ABC/Post poll completed Sept. 9.

In other results, Obama has a 49 percent job approval rating among likely voters - it's been 49 or 50 percent steadily since mid-October - but more "strongly" disapprove than strongly approve, 41 percent vs. 30 percent - an intensity gap that may work against him.

HORSE RACE - Romney never before has exceeded 49 percent support in ABC/Post polls, making his 50 percent a new high numerically. That includes new highs among a range of groups - including 60 percent support among whites, 56 percent among white women, 58 percent among middle- to upper-middle income adults and 83 percent among conservatives.

Most strikingly, Romney's advanced to 57 percent support among independents. They're a changeable group, less rooted in partisan predispositions, so their eventual preferences - and their turnout - are uncertain. But they're key to Romney's current fortunes; he's improved among independents by 9 points in the past week.

The debates are one apparent reason. By a broad 47-10 percent, independents say the debates left them with a better rather than a worse impression of Romney. In the same group, by contrast, just 17 percent say their impression of Obama improved - and 26 percent say it got worse.

Polarization, meantime, is extreme; Obama is at a new high in support among nonwhites, 80 percent, and continues to pull in broad support from younger adults - six in 10 of those younger than 40. All the same, at 61 percent, his support among unmarried women, a core Democratic group, has reached a new low, chiefly because he's slipped among unmarried white women.

Still, the gender gap overall remains wide: women for Obama by 54-43 percent; men for Romney by 57-40 percent.

As noted, the overall 3-point gap between Romney and Obama in this poll is not statistically significant. Given the sample size, it would take a difference of greater than 6 points for the result to be significant at the customary 95 percent confidence level, or more than 5 points at a less-stringent 90 percent confidence level (referred to as a "slight" or marginal difference).

While the race, then, remains close, Romney's momentum has come in time for most voters: Thirty-seven percent of likely voters say they've voted early or plan to, but that includes far fewer, 8 percent, who already have done so. It's a number that's growing daily, putting each campaign's get-out-the-vote efforts to the critical test.

METHODOLOGY - This ABC News/Washington Post poll was conducted by telephone Oct. 21-24, 2012, among a random national sample of 1,386 likely voters, including landline and cell-phone-only respondents. Results have a margin of sampling error of 3 points, including design effect. (Questions 12f, 12h and 21 were asked Oct. 23-24 among 707 likely voters; those results have a 4.5-point error margin.) 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.

Partisan divisions in this survey, Democrats-Republicans-independents, are 34-30-31 percent among likely voters. Partisan divisions in the 2008 exit poll were 39-32-29 percent.