Gov. Josh Shapiro of Pennsylvania, a moderate Democrat, is in the driver’s seat for re-election in a battleground state, according to a New York Times/Philadelphia Inquirer/Siena University poll.

Mr. Shapiro leads Stacy Garrity, the Republican state treasurer, by 16 percentage points among likely voters, according to the poll. He leads in nearly every demographic group and is winning 11 percent of President Trump’s 2024 supporters.

Throughout his first term, Mr. Shapiro has cultivated a pragmatic image focused on local issues, even while frequently denouncing the Trump administration and becoming a national figure in his own right. He was vetted as a potential running mate for Vice President Kamala Harris in 2024, and he is often discussed as a potential candidate for president in 2028.

The poll finds Mr. Shapiro running ahead of his own party in the state. When voters were asked which party they will support for Congress, Democrats had a six-percentage-point lead. That represents a better showing than 2024, when Mr. Trump narrowly carried the state, but is well below Mr. Shapiro’s margin.

A major factor in support for Mr. Shapiro is his performance as governor, with 60 percent of voters expressing their approval and a majority of Pennsylvanians saying they feel he is “about right” when it comes to his stance toward Mr. Trump. The president’s approval rating is 19 points underwater in the state.

Notably, while half of Pennsylvania voters said the Democratic Party was too far to the left, 29 percent said the same of Mr. Shapiro.

Ms. Garrity, a former Army Reserve officer, maintains a favorable image among voters familiar with her and is seen as less extreme than Republicans at large. The poll’s findings, however, suggest her image is much less defined than Mr. Shapiro’s: just under 40 percent of voters had no opinion of Ms. Garrity or said they had not heard of her when asked.

Voters across the political spectrum say their support in the governor’s race is largely driven by economic concerns. Mr. Shapiro had a 15-percentage-point lead over Ms. Garrity in his handling of the state’s economy and a 16-percentage-point lead in his dealing with the cost of living.

Another key issue is artificial intelligence data centers, which have been at the forefront of the midterm conversation nationwide. Mr. Shapiro recently signed an executive order imposing what he called the “strictest guardrails in the nation” on data center development — a sharp reversal from last year when he touted Amazon’s plans to invest $20 billion for A.I. infrastructure in Pennsylvania.

The switch puts him in line with a majority of Pennsylvanians, among whom nearly two-thirds of likely voters — including 42 percent of Republicans — said they were opposed to data center construction. Ms. Garrity, who remains supportive of continued development, accused him of flip-flopping.

Young voters broadly support Mr. Shapiro, with those under 30 backing him by a margin of around 40 percentage points. Those voters are more likely than older voters to agree with him on a range of issues, as is typical since younger voters tend to lean more Democratic, and two-thirds of them say he is not too far to the left or right ideologically.

The exception is Mr. Shapiro’s stance toward Israel. While 14 percent of Pennsylvania voters feel that Mr. Shapiro has been too supportive of Israel, that number balloons to 40 percent among voters under 30 — the same share as Ms. Garrity.

Mr. Shapiro, who is Jewish, has faced scrutiny for his past statements in support of Israel. In a memoir released earlier this year, he wrote that his views on Israel were intensely vetted when he was being considered as a running mate for Ms. Harris, to an extent he found offensive.

As he seeks a second term, and contemplates a presidential run, Mr. Shapiro is using competitive races in Pennsylvania as a proving ground for his political influence. “I’m doing everything in my power to rally the troops, raise funds, build an organization that can help not just win my own re-election, but help Democrats up and down the ballot,” he told The New York Times in an interview in May.

An overwhelming 86 percent of potential Democratic primary voters in Pennsylvania said they would consider supporting him for the party’s presidential nomination in two years, with nearly half saying they would be very likely to support him. Younger Democrats are slightly less likely to say they would consider supporting Mr. Shapiro — 27 percent said it was not likely — though a large majority still said they would consider him.

Some voters expressed concerns that a presidential run could take time away from Mr. Shapiro’s work as governor, though the issue was not seen as a major one. A majority of the voters acknowledged that a run for higher office would be distracting, but only 37 percent of voters — many of whom are Republicans — said a presidential bid by Mr. Shapiro would render him unable to be an effective governor.