PHILADELPHIA — A super PAC has been set up to boost U.S. Rep. Conor Lamb's campaign for Senate — and if it raises as much money as it aims to, it could help him close a financial gap against his Democratic primary rival, Lt. Gov. John Fetterman.

Messages sent to prospective donors this week, obtained by The Inquirer, set a goal of spending $8 million on TV ads and other paid media ahead of the Pennsylvania primary election in May.

Some big Pennsylvania Democratic donors got emails this week from famed political strategist James Carville introducing them to the group, Penn Progress, and inviting them to support it.

"I wanted to reach out to you about the single most important Senate race in the country this November which is being held in Pennsylvania," Carville wrote in one email. "There is no way that Democrats can expand our majority in the Senate if we do not pick up the Pennsylvania Senate seat and the best person to win that race is my good friend Conor Lamb. ... Conor has a tough primary, and I was hoping you could help him by supporting Penn Progress, the independent effort set up to help ensure Conor is our nominee."

In a memo Penn Progress sent prospective donors last fall, the group described itself as "veteran campaign strategists with thirty years of electoral experience in Pennsylvania and beyond."

Federal campaign finance laws put strict limits on how much individuals and many other political committees can give directly to political campaigns. Super PACs aren't subject to those contribution limits, meaning they can spend huge sums influencing elections. They're not allowed to coordinate their activities with the campaigns they support, or to contribute to them.

Penn Progress registered with the Federal Election Commission in September. It reported raising just $35,000 in 2021. Its memo lays out an ambitious goal of spending $8 million on paid statewide media, $200,000 on polling, and $60,000 on research, a website, and social media.

Steve Cozen, a prominent Philadelphia-area Democratic donor, contributed $10,000, according to the group's federal filing. Cozen had already contributed the maximum allowed to Lamb's campaign — $2,900 for primary and $2,900 for general election. The Sheetmetal Workers Union, which endorsed Lamb, gave the PAC $35,000.