US News, Paul Bedard

President Obama’s slow ride down Gallup’s daily presidential job approval index has finally passed below Jimmy Carter, earning Obama the worst job approval rating of any president at this stage of his term in modern political history.

Since March, Obama’s job approval rating has hovered above Carter’s, considered among the 20th century’s worst presidents, but today Obama’s punctured Carter’s dismal job approval line. On their comparison chart, Gallup put Obama’s job approval rating at 43 percent compared to Carter’s 51 percent.

Back in 1979, Carter was far below Obama until the Iran hostage crisis, eerily being duplicated in Tehran today with Iranian protesters storming the British embassy. The early days of the crisis helped Carter’s ratings, though his failure to win the release of captured Americans, coupled with a bad economy, led to his defeat by Ronald Reagan in 1980.

According to Gallup, here are the job approval numbers for other presidents at this stage of their terms, a year before the re-election campaign:

– Harry S. Truman: 54 percent.

– Dwight Eisenhower: 78 percent.

– Lyndon B. Johnson: 44 percent.

– Richard M. Nixon: 50 percent.

– Ronald Reagan: 54 percent.

– George H.W. Bush: 52 percent.

– Bill Clinton: 51 percent.

– George W. Bush: 55 percent.

What’s more, Gallup finds that Obama’s overall job approval rating so far has averaged 49 percent. Only three former presidents have had a worse average rating at this stage: Carter, Ford, and Harry S. Truman. Only Truman won re-election in an anti-Congress campaign that Obama’s team is using as a model.

Many pundits believe that job approval ratings are the key number to look at when determining if a president will win re-election. Generally, they feel that a president should be higher than 47 percent to win re-election.

Obama’s troubles have revived talk in Democratic circles that Vice President Joe Biden should be replaced by the politically popular Hillary Clinton. She plans to leave as secretary of state at the end of Obama’s term no matter what happens in the re-election.

A key Democratic source said that Clinton could help revive the Democratic base and bring in Clinton backers, with whom the administration has had a cool relationship. Clinton has repeatedly rejected talk of her swapping roles with Biden, but Democratic operatives eager to keep the president in office believe that she would be the key to winning educated white voters and liberals upset with the administration’s actions.