With a new poll showing Pennsylvania Democratic Rep. Joe Sestak edging in front in the Senate race, the Service Employees International Union (SEIU) announced it will spend $2 million to help him across the finish line.

The SEIU cash will go to its get-out-the-vote effort in support of Sestak and Democrat Dan Onorato, who's running for governor. The campaign includes a member outreach program and an independent expenditure (IE) effort, according to a release. It will focus on grassroots mobilization through canvassing, direct mail and phone banking.

"We're out talking to voters every day about the importance of electing leaders like Dan Onorato and Joe Sestak who understand the needs and priorities of working families," Gabe Morgan, SEIU Pennsylvania State Council president, said in a statement. 

The SEIU has some 100,000 members in Pennsylvania.

Meanwhile, the Allentown Morning Call/Muhlenberg College Tracker poll shows Sestak leading Republican Pat Toomey 44 percent to 41, with 15 percent undecided.