Written from wsj.com

A look at U.S. presidents’ job-approval ratings.

Truman became president after Franklin D. Roosevelt died at the start of his fourth term.

After a major heart attack in the fall of 1955, Eisenhower was elected to a second term a year later.

Kennedy’s ratings were well above 50% when he was assassinated.

Inheritor of the war in Vietnam, Johnson was unable to improve upon his inaugural highs.

Nixon struggled with Vietnam, too, but Watergate was what ended his presidency.

Appointed Nixon’s vice president after Spiro Agnew’s resignation, Ford finished Nixon’s term.

Carter made progress with the Camp David Accords, but the Iran hostage crisis ultimately hurt him.

Reagan survived two major downturns, during a recession and after Iran-Contra.

A reversal of his “No New Taxes” vow hurt George H.W. Bush, but the Gulf War was a diversion.

Clinton was stung by response to the Nafta trade pact, but floated atop impeachment concerns.

The Sept. 11 attacks prompted Americans to rally for George W. Bush, but the war in Iraq is wearing.

Sources: Gallup, AP, WSJ.com research?????????NOTES: Plotted points are the averages of all approval polls taken by Gallup in each three-month period of each presidency. The first two points for Johnson and Ford are for polls taken in their first two months. Key dates are marked next to the poll results for the three-month period in which they took place.