Robert Strong

Opinion contributor

Last week the Quinnipiac Poll put President Trump’s job approval rating at 33%. Gallup had it at 36% this week, as did a new CBS News poll. These are historically low numbers for the end of a president’s first six months in office.

Since the mid-1940s pollsters have tracked presidential approval with standard questions posed to significant samples of American adults. We have reliable numbers for more than 70 years and for 13 occupants of the Oval Office.

Approval numbers rise and fall, but a few patterns persist. For example, first terms are better than second terms. All the presidents after Franklin D. Roosevelt who served more than four years had a better average approval number in the period before election to a second term than in the period after. The drops were very small for Ronald Reagan and Bill Clinton, but significant for six others.

Every modern president before Trump had at least one approval number above 50%; and, with the exception of John F. Kennedy, all of them eventually earned an approval number below 50%. According to Gallup, Dwight D. Eisenhower’s low was 48%; the others dipped into the 30s or 20s.

Over time, presidential job approval tends to decline, often from a high point earned at inauguration when the voters who preferred another candidate give the victor a new look.

Though decline is the norm, it is not universal. In terms of public approval, there are two categories of recent presidents: “sliders” and “risers.”

The sliders (by far the larger group) achieve their highest approval rating on arrival in the White House or sometime during their first year in office. Then they fall. That pattern describes Kennedy, Harry Truman, Lyndon Johnson, Richard Nixon, Gerald Ford, Jimmy Carter, George W. Bush and Barack Obama.

Four of our recent leaders — Eisenhower, Reagan, George H.W. Bush and Clinton — are risers who earned their highest approval number sometime after their first year in office.

Trump, thus far, is highly unusual because he has never had a Gallup job approval number above 50%. He began his administration with approval in the high 40s and has since slipped into the mid-30s. If he continues to be a slider, he will be the first president in the history of national polling to never earn the support of a majority of Americans — a remarkable distinction.

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And why do approval numbers slide? Low approval is often accompanied by one or more of the following conditions: weak economic performance, unpopular overseas conflicts, and/or solid evidence of high-level scandal.

Carter reached a low point after oil shocks and inflation created economic hardship and uncertainty. Truman, Johnson and W. Bush suffered for Korea, Vietnam and Iraq, respectively. Nixon got his lowest numbers at the height of Watergate revelations.

Low numbers are easy to explain.

The unusual thing about Trump is that he has earned low approval at a time when economic metrics are good, when our Middle East military commitments have diminished, and when no proof has yet emerged that there are actual witches in the “witch hunt” over Russia. What will happen if bad news arrives in the Trump Oval Office?

Odds are that Trump’s low numbers will go lower, but we can’t count out the possibility that he will be a riser. What accounts for presidential approval going up? In many cases, the uplifting factors are the opposites of the causes of decline.

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When the country comes out of a recession and the economy feels like it is getting better, presidents get higher approval numbers. This happened for Reagan after the deep recession early in his first term and for Clinton throughout much of the 1990s.

Though the long-term effects of overseas conflict on presidential approval are often negative, at the outset of a crisis the public tends to support their leader. The two Bush presidents shot up in public appeal when the U.S. fought the first war against Saddam Hussein and when the country was attacked on 9/11. Even a foreign policy disaster —the Bay of Pigs for Kennedy or the taking of hostages in Iran for Carter — can cause Americans to temporarily rally round an embattled commander in chief.

Scandals that damage, but don’t destroy, a presidency — Reagan’s Iran-Contra or Clinton’s impeachment — often end with modest improvement in public approval.

Will the Trump presidency see better economic numbers, an overseas crisis that does not become a controversial conflict, or favorable resolution of current investigations? Perhaps. But a more likely prediction is that Trump, like most presidents, will experience a decline from his initial approval numbers.

That would raise an awkward question: how low can Trump go when his current job approval is weaker than any we have ever seen six months into a new administration?

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Robert Strong is the William Lyne Wilson Professor of Politics at Washington and Lee University.

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