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President Obama holds most of the cards in fiscal cliff negotiations with the Republican leaders of Congress, with more Americans approving of his handling of the talks and more prepared to blame the GOP if the brinksmanship fails. But another factor constrains the president: His lack of a mandate in the public's mind.

Overall, the latest ABC News/Washington Post poll shows the impact of Obama's successful re-election campaign. His job approval rating, at 54 percent, is his highest (excepting a brief bin Laden bounce) in nearly two years. And even while weakly rated on the economy, he leads the Republicans in trust to handle it by 18 percentage points, his widest margin since July 2009.

See PDF with full results, charts and tables here.

But for all his advantages, Americans by a wide 22-point margin, 56-34 percent, say Obama does not have "a mandate to carry out the agenda he presented during the presidential campaign," but rather should "compromise on things the Republicans strongly oppose," a sign of risk for the president if the talks should collapse.

The sense Obama has a mandate, notably, is 16 points lower than it was after the 2008 election, suggesting a more restricted range of political possibilities in his second term. The decrease is broadly based, occurring across groups save Democrats and nonwhites.

Reflecting the GOP's challenges in opposing tax cuts on the wealthy, Obama leads especially widely, by 26 points, 58-32 percent, in trust to protect the middle class - a perception he wielded to great effect against Mitt Romney in the 2012 campaign. Obama's lead on the economy is double what it was at the start of the year, higher notably among moderates and independents.

More generally, this poll, produced for ABC by Langer Research Associates, shows a 12-point advantage for Obama in trust to handle the main problems the nation faces over the next few years. That includes a 9-point edge among political independents.

WATCH OUT FOR THE CLIIIIIFFF - There's risk for both sides on the fiscal cliff, with broad worry about the potential consequences of a budget crisis, and most solutions unpopular. While Obama holds the high ground on taxing the wealthy, for instance, the Republicans can point to plurality preference that a budget deal rely more heavily on spending cuts than on tax increases.

Obama gets just an even split on his handling of the budget negotiations, 45-43 percent, approve-disapprove - but that's far better than the more than 2-1 negative rating on the issue for the Republican leaders of Congress: 26 percent approve, 65 percent disapprove. One reason: Obama has 75 percent approval in his own party; the Republicans, just 53 percent in theirs. And the president's rating doubles the GOP's among independents.

Obama also holds an advantage in perceived flexibility: While 57 percent say he hasn't been willing enough to compromise, many more, 76 percent, say that about the GOP leaders. Indeed, 28 percent say Obama is "too willing" to compromise, while just half as many say that about the GOP.

Perhaps surprisingly, more than half, 53 percent, are optimistic the two sides will agree on a budget plan - though just 14 percent think it's "very" likely. (Optimism peaks among Democrats and liberals.) If a deal is not reached, more think the GOP will be to blame than Obama by a 16-point margin, 47-31 percent, while an additional 18 percent say both sides will share the blame.

IMPACTS and OPTIONS - A vast majority (89 percent) expresses concern about what may happen to the national economy if a budget deal is not reached, with 58 percent very concerned. Three-quarters or more also express concern about how a lack of an agreement will impact their personal finances, the government's ability to operate effectively and the U.S. military.

In terms of options for a solution, as noted, the Republicans have some pushback to Obama's advantages. Assuming a mix of spending cuts and tax increases, a plurality, 47 percent, says spending cuts should be the biggest slice of the pie. A fairly close 41 percent favor an equal division; just one in 10 wants more tax increases than cuts in spending.

On the other hand, most of the current spending cuts being discussed in Washington are seen as broadly unacceptable to the public, making the negotiations look like an exercise in picking the least-worse options. Nearly seven in 10 say they would find cuts to Medicaid unacceptable, six in 10 say the same about raising the age for Medicare coverage and for slowing the rate of increases in Social Security benefits, and 55 percent rule out military cuts.

Indeed the only budget-deal items tested that are perceived as broadly acceptable are those that would raise revenue: Three-quarters of Americans say raising tax rates on incomes greater than $250,000 would be acceptable, and 54 percent back capping the amount of money people can claim in tax deductions at $50,000.

PRESIDENT and PARTY - This survey, as noted, marks out Obama's broader political standing. His approval rating for handling the economy, while just 50 percent, is its highest in two and a half years. And he's on par with the GOP in trust to handle taxes, 46-42 percent, and the deficit, 45-41 percent.

Some of this rubs off on Obama's party: While just 39 percent approve of the way the Democrats in Congress are doing their job, that's up from a record low of 27 percent a year ago. And it's 14 points better than the approval rating for the Republicans in Congress.

Finally, matching his approval rating, 54 percent of Americans view the outcome of the election positively. And more are enthusiastic about the outcome, albeit just 23 percent, than the 13 percent who are angry about it.

GROUPS - Traditional partisan and ideological differences dominate preferences on the deficit. Fifty-two percent of Democrats favor an even split of spending cuts and tax increases, while 50 percent of independents and 71 percent of Republicans would mostly cut spending. Twenty-two percent of Democrats would mostly increase taxes, vs. only 7 and 1 percent of independents and Republicans, respectively.

Cutting Medicaid spending and increasing the Medicare eligibility age are seen as unacceptable by half of Republicans and strong conservatives, groups that usually favor spending cuts. Majority opposition to cutting military spending, meanwhile, is driven by Republicans and strong conservatives, among whom broad majorities say it's an unacceptable option. Democrats and liberals favor these cuts, but at lower levels than the opposition among others.

By contrast to the other proposals, raising taxes on the well-off gains favor across the board, including bare majorities of Republicans and strong conservatives, as well as 77 percent of independents and 81 percent of moderates. Capping tax deductions lacks support that high - but, at the same time, does no worse than an even split among Republicans.

METHODOLOGY - This ABC News/Washington Post poll was conducted by telephone Dec. 13-16, 2012, among a random national sample of 1,002 adults, including landline and cell-phone-only respondents. Results have a margin of sampling error of 3.5 points, including design effect. Partisan divisions are 31-24-38 percent, Democrats-Republicans-independents.

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.