An economy on the mend hasn't convinced the public that President Obama is doing a good job.

Obama's plight was reinforced by a Washington Post-ABC News poll released this week. Signs of economic recovery, that Americans say they feel, have done little to boost the president's approval rating, which is mired in the low 40s.

As they seek to right the ship after a disastrous 2013 rife with legislative and political setbacks, Obama and his team should find it troubling that one of the year's few bright spots has done little to boost the president's political standing ahead of a 2014 campaign in which his image will be inexorably tied to many Democrats running for office.

Why wouldn't positive signs on the issue Obama campaigned on and made a centerpiece of his agenda boost the public's opinion of him? There are a few plausible reasons. But first, let's take a closer look at the numbers.

Obama's approval rating is an unimpressive 43 percent in the new poll, with 55 percent of adults saying they disapprove of the job he is doing. And his approval rating split (42/55) when it comes to the economy is nearly identical.

But it's not because Americans think the economy is stagnating. Fifty-nine percent say they personally feel the economy has begun to recover. Just 39 percent say they don't feel the recovery. Longer-term trends show that as Americans' opinions of the economy have grown rosier, Obama's approval rating hasn't followed suit.

The findings come as there have been broad if incremental signs of economic improvement.

In a fall and early winter chock-full of bad news, Obama got some good news earlier this month in the form of a monthly report that showed the U.S. economy grew by more than 200,000 jobs in November, and the unemployment rate fell to its lowest level in five years. The boost continued months of solid gains – gains that have done little to reverse the views of a public that has soured on the president.

So what's going on here? Why isn't encouraging economic news lifting Obama's approval rating? There are a few likely explanations.

First, most positive economic news has been overshadowed by attention to problems with the Obamacare rollout, the government shutdown showdown, and revelations about government surveillance.

Second, while Americans indeed see a recovery, they don't see a very robust one. Only a quarter of those who feel a recovery say it’s been a strong rebound – 15 percent of the overall public – while 44 percent say it’s been weak.

This tepid assessment could also explain Obama’s low approval rating on the issue of the economy, specifically. It’s also supported by the reality of an unemployment rate that while declining, is still above pre-recession levels in the early and middle parts of the last decade.

A third reason is that Americans' interpretations of the economy – and Obama’s role in it -- are consistently colored by political biases. Three quarters of Democrats (75 percent) say they feel the economy has begun to recover, compared with only 47 percent of Republicans, a perception divide that has existed since 2009 on this question (and before then on others).

Democrats are far more apt to recognize economic improvement and credit Obama for causing them, while Republicans are less likely to do so. This dynamic undermines the ability of modest economic shifts to shake political assessments.

From a policy perspective, Obama may argue -- as he did in the 2012 campaign -- that the trajectory of the economy is a reflection of his team's approach and the fixes it deployed.

But from a political viewpoint, there has been little for the president to celebrate this year -- even on a front where there's been good news for him.