At first blush, the reaction to this Gallup poll is … so what?  Barack Obama managed to get himself elected to a second term anyway, even with historically anemic approval numbers.  But there’s more to this than just last November:

President Barack Obama averaged 49.1% job approval during his first term in office, among the lowest for post-World War II presidents. Only Jimmy Carter and Gerald Ford had lower job approval averages. Obama’s first-term average is most similar to Bill Clinton’s. Lyndon Johnson, John Kennedy, and Dwight Eisenhower were the most popular first-term presidents.

Obama’s first-term approval average, like those of most presidents with lower first-term averages, was likely dragged down by a sluggish economy. Clinton and Reagan saw higher second-term approval as the economy improved. Obama’s approval rating has also shown improvement, with a 48.1% average in his fourth year in office after a 44.4% average in his third year.

Obama has recently rebounded, but it’s still not terribly impressive from a historical standpoint:

The more recent positive trend in evaluations of Obama is evident in his quarterly averages. For his 16th quarter in office, from Oct. 20 through Jan. 19, he averaged 51.9% approval. That was his first quarterly average above 50% since his fourth quarter in office. Obama has seen at least modest improvement in his job approval average each of the last five quarters, since a term-low 41.0% in his 11th quarter in office. That quarter was marked by contentious negotiations to raise the federal debt ceiling, and an ensuing drop in the stock market while unemployment remained high.

Even at 51.9%, Obama doesn’t have much momentum rolling into his second term.  That only puts him above Reagan and Clinton, neither of whom were known for their second-term agendas.  George W. Bush had a 62.2% average approval rating in his first term, and the combination of a botched attempt to reform Social Security and the Hurricane Katrina disaster ended any hope of making headway in a second term on domestic politics, while the worsening war in Iraq eroded what was left of his political capital.

Why does this matter for Obama? He will argue this week, starting today, that the American people validated his agenda, but clearly that’s not the case.  He became the first post-WWII President to win re-election with fewer votes, and his approval ratings have perked up in the wake of the fiscal-cliff deal, but he’s hardly in the driver’s seat.  Moreover, the one policy for which Obama might have legitimately claimed a mandate from the election — higher taxes on the wealthy — has already passed at the end of his first term.

Small wonder that Politico takes a pessimistic view of Obama’s opportunities in a second term:

But presidential closing acts tend to be periods of reaction rather than action. Even the strongest and most proactive chief executives find themselves bowing to events, a process not unlike watching the battery of an iPhone slowly die — with many messages still left to be returned.

Obama, who has made a habit of bucking historic trends, is hoping to defy the second-term curse. He’ll try to transform his campaign organization, with its millions-strong lists of supporters, into a new force for fundraising and mobilization to pressure Republicans and Democrats who don’t support his agenda. …

Obama’s convincing win over Mitt Romney in November has proven to be a powerful lever in his negotiations with Republicans so far, contributing to his success in fiscal cliff negotiations and helping to drive his approval numbers into the mid-50s for the first time in years. People close to the president cite the 2012 win as a liberating event, one that freed him to stand tough against his enemies. The problem — and it grows with each passing day leading up to the next election — is that Obama’s damn-the-torpedoes attitude is out of sync with the mind-set of his own party. Twenty Senate Democrats face reelection in 2014, compared with 13 Republicans, many of those Democrats in hard-to-hold states like North Carolina, West Virginia, Louisiana and Arkansas. “He’s never been really that attuned to the Hill in the first place,” says a former Obama aide. “Now that he’s not running for anything, he’s increasingly out of sync. That increases the likelihood he leads and no one follows.”

Historically speaking, not too many are following him now.