WASHINGTON (AP) — Donald Trump started as the most unpopular new president in the history of modern polling. After seven months, things have only gotten worse.

Plunging into undesirably uncharted territory, Trump is setting records with his dismally low approval ratings, including the lowest mark ever for a president in his first year. In fact, with four months left in the year, Trump has already spent more time under 40 percent than any other first-year president.

At 34 percent, his current approval rating is worse than President Barack Obama's ever was.

Trump's early descent in the polls defies some longstanding patterns about how Americans view their president. Such plunges are often tied to external forces that the president only partially controls, such as a sluggish economy or an all-consuming international crisis. In Trump's case, the economy is humming and the foreign crises have been kept to a minimum.

Americans also tend to be optimistic about their new leaders, typically cutting them some slack during their early days in office. Not with Trump.

"Most presidents begin with a honeymoon period and then go down from that, and Trump had no honeymoon," said Gallup editor-in-chief Frank Newport.

It's a jarring juxtaposition for the reality TV star-turned-president who spent months on the campaign trail obsessing about his poll numbers and reading them to massive rally crowds while vowing that he'd win so much as president that Americans would get sick of it. Since he took office, the poll number recitations have stopped.

Trump is now viewed positively by only 37 percent of Americans, according to Gallup's most recent weekly estimate. (Obama's lowest weekly average never fell below 40 percent.) It's even lower — just 34 percent — in Gallup's shorter, three-day average, which includes more recent interviews but can also involve more random variation.

To be sure, approval ratings can fluctuate — sometimes dramatically. Some presidents have seen their positive reviews dip below 40 percent, only to recover strongly. Bill Clinton, whose rating fell to 37 percent in early June 1993 after policy stumbles, quickly gained ground. Later that same month, he climbed to 46 percent, and ended his eight years enjoying approval from 66 percent of the nation.

Trump has defied the trends before. But if history is a guide, his numbers don't bode well. Low approval ratings hamper a president's ability to push an agenda through Congress and make it more likely the president's party will lose seats in Congress in the midterm elections.

Scott de Marchi, who teaches political science at Duke University, says his research suggests approval ratings tend to affect whether a president can persuade Congress to do his or her bidding. That's primarily true with complex issues like tax reform, where Americans care about the outcome but may not have strongly formed opinions. In those cases, Americans are more likely to support whatever plan the president proposes if they broadly approve of the president himself.

"The problem with Trump is that on any area like the budget or tax policy or even health care, people need to be led to a position to support," de Marchi said.

Since Gallup began tracking presidential approval, four presidents — Harry Truman, Gerald Ford, Jimmy Carter and George H.W. Bush — spent significant time below 40 percent during their first four years. Clinton's and Ronald Reagan's forays below the 40 percent mark also came during their first terms. But neither stayed there long.

Of those who spent at least a few months below 40 percent approval in a first term, only one — Truman — recovered enough to win re-election.

Still, several others reached lows at some point in their presidency that are worse than Trump's, including several who dropped below 30 percent.

Truman hit 22 percent in February 1952, during a drawn-out Korean War stalemate and accusations of corruption in his administration. Richard Nixon hit 24 percent at the height of the Watergate scandal just before his resignation in 1974. Carter bottomed out at 28 percent in the summer of 1979, amid that year's oil crisis.

Trump's average approval rating so far: Just 40 percent. That's even lower than the previous average low for a first-term president, 46 percent, set by Carter.

Newport, the Gallup chief, said Trump's struggles are unusual in that such abysmal numbers can usually be tied to a single, specific issue bedeviling the country. With Trump, Newport said, "it's a more general kind of issue with the man himself and a more general dissatisfaction with the way things are going in the country."

In July, Gallup posed another question to Trump's disapprovers: Why? Nearly two-thirds cited his personality or character, while less than a third cited issues, policies or job performance.

By contrast, when Gallup asked the same question about Obama in 2009 and George W. Bush in 2001, less than 2 in 10 disapprovers cited similar concerns about personal characteristics.

The vast majority of Republicans support Trump while the vast majority of Democrats oppose him. Such political polarization might be both a blessing and a curse for Trump, preventing him from achieving higher ratings but also keeping him from falling even further.

"When Trump has done things that have generated an enormous amount of attention and people have anticipated his rating could go down, it has not," Newport said. "And that's because he's being propped up by Republicans."

It's unclear whether Trump's most recent bout with controversy — his response to racially tinged clashes in Charlottesville, Virginia — further harmed his approval ratings. It could be he's close enough to bottoming out that the latest dust-up will have little effect.

In a Washington Post-ABC News poll conducted Aug. 16-20, just 28 percent said they approve of Trump's response to Charlottesville. But 37 percent said they approved of the job Trump is doing overall — almost the exact same percentage that approved in the same poll a month earlier.

Yet if the famously image-conscious Trump aspires to undo some of the damage, there's reason to hope.

"The history of presidential job approval ratings shows an enormous amount of fluctuation," Newport said. "There's no historical reason why his ratings couldn't go up."