The Pennsylvania Democratic Party is deploying a familiar strategy against one of the GOP’s favorite recruits for the 2024 Senate competition there, David McCormick, attacking him for residing primarily at Connecticut.

In a large, colorful font placed next to a frowning photo of Mr. McCormick, a new billboard paid for by the Pennsylvania Democratic Party reads: “Connecticut, Home of David McCormick.”

The billboard arrives in the wake of an Associated Press report from last week that found that while Mr. McCormick owns a home at Pittsburgh, he resides at Connecticut’s “Gold Coast,” an area known for its wealthy residents. 

It’s clear from Democrats’ reaction to the report that they sense this could be a vulnerability for Mr. McCormick. In last year’s Senate election in Pennsylvania, Senator Fetterman and his allies hammered Mehmet Oz for buying a home in Pennsylvania shortly before the election.

Seeking office in Pennsylvania isn’t a technical or a legal issue for Mr. McCormick while residing at Connecticut — the Constitution only requires senators to reside in their states at the time of the election — but it could be a liability in terms of public perception. Mr. Fetterman has already gone on the offensive against Mr. McCormick on the point.

Even though the GOP primaries for the Pennsylvania Senate race haven’t yet begun in earnest, it’s clear that the national GOP is courting Mr. McCormick as a top recruit for the race.

Mr. McCormick narrowly lost the GOP nomination in Pennsylvania in 2022, falling to Dr. Oz by 951 votes in the statewide primary.

While the national party apparatus took a hands-off approach in 2022, allowing President Trump to elevate Dr. Oz in the primary, the GOP’s National Republican Senatorial Committee appears to be getting involved in 2024 in the hopes of unseating Senator Casey.

The chairman of the NRSC, Senator Daines, told Reuters in July that he was “pleased to see Dave give this serious consideration,” and that he thinks Mr. McCormick “would be a great candidate.”

“I want to see candidates that can win not only a primary election, but importantly can win a general election and appeal to independent voters,” Mr. Daines said. “David McCormick would fit that profile.”

Mr. McCormick has also said that he is considering another bid for Senate and is expected to make a final decision this fall. Early polling from the Commonwealth Foundation suggests that he would have the largest immediate group of supporters of any challenger to Mr. Casey.

The survey found that 17 percent of respondents wanted Mr. McCormick to run for Senate. Another 14 percent wanted Dr. Oz to run for Senate again. Pennsylvania’s treasurer, Stacy Garrity, garnered 7 percent support, while Ambassador Carla Sands was at 6 percent and Congressman Keith Rothfus was at 4 percent.