The Democratic incumbent leads Romney among registered voters by 48 percent to 44 percent, a slight reduction from his 49 percent to 43 percent lead in July.
But other findings show that Democratic attacks have continued to damage his personal reputation, while his new running mate Paul Ryan has elevated a debate over Medicare that so far works to the disadvantage of the Republican ticket. (Related: Ryan's Way: How He Would Change Medicare.)
“Mitt Romney is sliding in the wrong direction,” said Democratic pollster Peter Hart, who conducts the Journal/NBC survey with his Republican counterpart Bill McInturff. “As the debate shifts away from being solely about jobs, Romney’s position weakens.”
Though a sour public mood and weak ratings on the economy continue to weigh on the president, Hart said Ryan’s identification with far-reaching changes to the popular Medicare program has created a counterpoint that benefits Democrats.
“This election has moved from a referendum (on the economy) to a choice election, “ he said. “The Medicare issue gives (Obama) a hammer he didn’t have before now.”
Obama’s lackluster job approval rating, 48 percent, matches the proportion of voters who have a favorable personal impression of him.
Some 43 percent regard him unfavorably.
But Romney’s 44 percent unfavorable rating — his highest of the campaign — exceeds his 38 percent favorable rating. That reflects the unprecedentedly heavy investment Obama and his Democratic allies have made in sullying the former Massachusetts governor’s reputation this summer.
Romney will have a chance to tell a more positive story about himself next week at the Republican National Convention in Tampa. But even before then, because of the ad barrage in swing states, “We’ve had a functional presidential race,” McInturff said. “it’s already occurred.”
Pounding by Democrats on Romney’s refusal to release more than two years of his tax returns has taken a significant toll. (Related: Romney Says He Paid at Least 13% Taxes for 10 Years.)
Some 36 percent of voters say what they’ve heard about that issue makes them feel more negatively about Romney; just 6 percent say it has made them feel more positively. By a narrower 28 percent to 25 percent margin, voters say what they’ve heard about his business experience makes them feel more negatively.
Nor is Romney helped so far by increased attention to Ryan’s plan to overhaul Medicare through a shift to vouchers giving beneficiaries vouchers worth a fixed amount for the purchase of private health insurance coverage. Some 30 percent of voters call that a bad idea, while 15 percent embrace it.
By 50 percent to 34 percent, voters say they agree more with Obama than Romney on the issue. More broadly, 54 percent of voters say Medicare needs no more than minor modifications, compared to 42 percent who prefer major changes or a complete overhaul.
McInturff noted Republicans still have an opportunity to change the terms of the debate, which they’ve attempted in recent days by accusing Obama of cutting Medicare spending to finance his 2010 health care overhaul. (Related: Health Care Investors Bet on Obama in November.)
Partisan polarization and the swelling volume and velocity of political information have muddled Ryan’s debut as Romney’s running mate. “You just don’t get an easy introduction anymore,” McInturff said. (Related: Romney's Pick of Ryan Seems to Energize Both Sides.)
The Wisconsin representative, who chairs the House Budget Committee, was rated positively by 33 percent of voters, negatively by 32 percent. Some 22 percent said his selection would make them more likely to vote for Romney, while 23 percent said it would make them less likely.
Romney can’t expect any lift from Ryan’s identification with Congress. Just 12 percent of voters approved of the job Congress is doing, while 82 percent disapprove — the worst rating for Congress in the NBC/WSJ poll’s two-decade history. (Related:NBC/WSJ Poll: 82 Percent Disapprove of Congress.)
By 47 percent to 42 percent, voters say they want Democrats to win control of Congress in November — an uptick from the Democrats’ one-point edge in July. The telephone survey of 1,000 registered voters, conducted Aug. 16-20, carries a margin for error of 3.1 percentage points.
Romney retains an edge on the electorate’s top concern. By 44 percent to 38 percent, voters credit Romney with better ideas for improving the economy. He also has an advantage on “executive and managerial skills” (45 percent to 32 percent) and “changing business as usual in Washington” (37 percent to 31 percent). (Related: Stark Differences in Ryan, Romney, Obama Tax Plans.)
Yet on a series of other qualities, voters prefer Obama. By 58 percent to 23 percent, they favor the incumbent on “being easygoing and likable”; by 52 percent to 24 percent on “dealing with issues of concern to women”; by 52 percent to 30 percent on “caring about average people”; by 45 percent to 38 percent on “being a good commander-in-chief”; by 46 percent to 35 percent on “being knowledgeable and experienced enough to handle the presidency.”
Romney “has a lot of repair work to do on his image,” Mr. Hart concluded.
—By CNBC's John Harwood