WASHINGTON — President Trump returns to Pennsylvania on Wednesday still seeking one of those big wins he has promised so often.

He'll arrive for a speech just outside Harrisburg to drive support for a tax-reform plan — the best remaining chance for a major legislative victory in his first year, when a president's power is typically highest.

But the event arrives with Trump again spending much of his energy on personal and cultural feuds rather than policy work. It would be little surprise if festering battles with fellow Republicans or NFL players feature just as prominently Wednesday as taxes.

"The first year is slipping away from him, and, for example, if he doesn't make good on tax reform, what's left of his top two or three agenda items?" asked Barbara Perry, director of presidential studies at the University of Virginia's Miller Center.

With a closing window for action and worsening poll numbers, Trump hopes to rouse support in a state that has played a continuing role in his presidency.

A major upset in the Keystone State helped secure him the White House. He traveled to Philadelphia shortly after his inauguration, where he told Republican lawmakers he'd keep them busier than ever signing new laws. And in April he marked his 100th day in office in Harrisburg by promising that a major win — repealing Obamacare — was around the corner.

"You watch," he told the crowd.

But months later, the Affordable Care Act remains in place, and Trump has done more to attack what he is against than advance what he is for.

His policy achievements have consisted mainly of shredding parts of former President Barack Obama's legacy — erasing regulations, scrapping a major international trade agreement and the Paris climate accord, suggesting he might unravel the Iran nuclear deal, and, this week, rolling back a policy meant to curb greenhouse-gas emissions and hinting at an executive order to institute health-care changes.

On Wednesday, Trump is expected to promote his tax plan before about 1,000 at the Harrisburg Air National Guard Base in Middletown. The script calls for him to explain how the plan would help middle-class workers like truck drivers, according to a senior White House official who briefed reporters on the condition of anonymity. The smaller setting is aimed at focusing attention on individuals who would benefit, the official said, with Trump telling their stories.

But while the aide delved into details of the plan, Trump has spent recent days lashing out at ESPN and NFL players who kneel during the national anthem, as well as Sen. Bob Corker, a Tennessee Republican who could be critical to the president's goals.

"He has no meaningful achievements," said Rep. Brendan Boyle (D., Pa.), who described the rallies as a way for Trump to feel good about himself in front of his most enthusiastic supporters. "It's a great way to distract them from his legislative failures."

Trump blames congressional Republicans for failing to deliver key votes, and his allies say the president has not gotten the credit he deserves, particularly for putting the conservative Neil Gorsuch on the Supreme Court, managing the national response to three massive storms (a point of sharp dispute), and showing steel to North Korea.

"He's done what he said he was going to do. Congress needs to work on tax reform and repealing Obamacare," said Val DiGiorgio, chairman of the Pennsylvania Republican Party. "The economy's doing great, consumer confidence is up, the stock market is up, and people that I talk to in business are happy that the size of government bureaucracy and the regulatory state is being cut back."

Some GOP lawmakers, however, argue that they need the White House to help sell big-ticket plans to the public, fretting as Trump instead focuses on unrelated conflicts, sometimes with his own cabinet.

"On tax reform, I think it's important that the president lay out his plan, his policy, and then go out and sell it," said Rep. Charlie Dent, an Allentown Republican and frequent Trump critic. "The president needs to remain focused and disciplined."

For some of his most devoted supporters, Trump's battles are part of the appeal. While adding gasoline to smoldering cultural fires, the president gives voice to his base's frustrations, even at the cost of alienating large swaths of the country.

Consider another recent rally, when Trump visited Alabama to campaign for Republican Sen. Luther Strange only to veer off into an attack on NFL players who kneel during the national anthem. His administration continued to probe that divide Sunday when Vice President Pence made a public show of leaving an Indianapolis Colts game — on the same weekend that Trump launched into a brutal war of words with Corker, who called the White House "an adult day care center."

Rep. Lou Barletta (R., Pa.), a close ally from Hazleton, said Trump was following through on his pledge to take on typical politicians and prod them for results, regardless of niceties.

"Anytime he gets in one of these fights, he wins," said Barletta, who plans to attend the speech. "He's encouraging Washington to keep pace."

If such battles please his supporters, though, they don't help in Congress.

Corker's support could be critical to the tax plan, given the GOP's two-vote Senate majority, and he leads the Senate Foreign Relations Committee, which oversees diplomatic appointments.

Just 24 percent of Americans believe the country is heading in the right direction, according to an Associated Press-NORC Center for Public Affairs Research poll released last week, including only 44 percent of Republicans.

In Pennsylvania, a Morning Consult poll showed Trump's net approval rating falling from positive 10 percent in January to negative 6 percent in September, part of a drop in several swing states.

If his numbers keep dropping, more lawmakers eyeing reelection could abandon him, potentially dooming any major legislation, said Perry, the Virginia professor.

Still, Trump won last year by defying polls. And as he tries to turn campaign boasts into reality, he's hoping Pennsylvania can help him again.