Hammered by bipartisan discontent with its partisan rancor, the U.S. Congress reconvenes Tuesday with its lowest approval rating on record in polls dating back nearly 40 years - ideal fodder not just for late-night comedians, but also for President Obama in the election year ahead.

Just 13 percent of Americans in the latest ABC News/Washington Post poll approve of the way Congress is handling its job, while 84 percent disapprove - its worst rating in poll results since 1974. Sixty-five percent disapprove "strongly," a vast level of high-intensity criticism.

Congress' rating is a broad 35 points below Obama's 48 percent approval, the biggest gap between approval of the president and Congress since 1990. Obama, though, still has plenty of challenges of his own: In polling since 1940, just four previous presidents have started their re-election year with less than 50 percent approval. Only one of them won, Richard Nixon in 1972. 

Nonetheless, the squabbling that's riven Congress the past year gives Obama one clear strategy - joining in the chorus of criticism of Congress, and the Republicans in Congress in particular. Their 21 percent approval rating is a point from its record low, set just last month.

The Democrats in Congress, at 33 percent approval, do better than their GOP counterparts, and have gained 6 points from their low last month. But they've moved in tandem with the Republicans: Both parties in Congress have lost 17 points in approval in the past three years.

Given the partisan and ideological nature of Congress' wrangling, it's striking how disapproval of the institution crosses the country's political landscape. This poll, produced for ABC by Langer Research Associates, finds that disapproval is equally high - 84 to 86 percent - among Democrats, Republicans and independents, and conservatives, moderates and liberals alike.

Indeed it peaks at both ends of the spectrum: Ninety-one percent of conservative Republicans disapprove of Congress, as do 90 percent of liberal Democrats - one thing, at least, on which they agree.

AND OBAMA - Unlike Congress, there are sharp partisan differences in Obama's approval rating - from a high of 90 percent among liberal Democrats to a low of 7 percent among conservative Republicans. While he does well with racial minorities, just 40 percent of whites approve of his work in office, as do just 43 percent of political independents, the key swing voters in national politics. Both, though, are up from their lows, 34 percent in both groups in October.

Obama's 48 percent approval is up from his career-low 42 percent in October, albeit essentially flat from last month's 49 percent. As noted, in data since 1940, four other presidents have gone into their re-election year with approval ratings under 50 percent - Lyndon Johnson, Richard Nixon, Gerald Ford and George H.W. Bush.

vs. CONGRESS - Comparisons of the president and Congress contain an element of unfairness, since even in tough times a president usually retains core supporters within his own party, a base unavailable to a sausage-making Congress. It's notable, nonetheless, that ratings of Congress have remained flat on the floor since fall, even as Obama's gained 6 points. 

Moreover, as noted, the 35-point difference between approval of the president and of Congress is its highest since 1990. And the ratio between the two is its highest on record: On average the past 38 years, there've been 1.5 approvers of the president for every approver of Congress. Today that's peaked at 3.7 - a comparative advantage that Obama is likely to stress regularly between now and Nov. 6.

BACK STORY - Congress fell off the approval cliff last summer amid the budget squabbling that led the country to near-default; it went from a dismal-enough 28 percent approval a year ago to half that in October. Disapproval has gained 18 points in the past year, "strong" disapproval, 22 points.

Congress rarely is popular in and of itself; its approval rating has averaged 38 percent in nearly 120 polls by ABC and the Post since 1988, and Gallup previously dating to 1974. In general it's harder to like an institution than an individual, and the political divisions within Congress mean there's always something there for someone to dislike.

Still, Congress has achieved popularity, peaking at 59 percent approval in December 2001, part of the post-9/11 rally, but also in the mid-50s in 1998, 1989, 1987 and 1985. It can be popular, though it rarely is.

Nor is Congress necessarily more unpopular when control of the House and Senate is divided, as now.  Again since 1974, its approval rating when divided has been 42 percent, the same as when it's been under Republican control, albeit better than its 33 percent when the Democrats have run the shop.

Looking ahead, the economy is the clear issue for the president: His approval rating is 80 percent among people who say they've gotten better off financially under his presidency, vs. 18 percent among those who've become worse off. For Congress, though, economic advances offer little hope: Its ratings are dismal, 9 and 17 percent respectively, among the worse-off and the better-off alike.

METHODOLOGY - This ABC News/Washington Post poll was conducted by telephone Jan. 12-15, 2012, among a random national sample of 1,000 adults, including landline and cell-phone-only respondents. Results have a margin of sampling error of 3.5 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.