Washington (CNN) - Sen. Arlen Specter released a new campaign ad Tuesday featuring actor Michael J. Fox.
The ad touts the five-term senator's support for medical research. "In the fight against disease, you can look back or move forward. Arlen Specter is moving forward," Fox says in the ad. "He's won the battles to double funding for biomedical research to find cures and save lives."
Appearing alone during the ad, Fox goes on to say, "The next discovery is right around the corner; that's why we need Arlen back in the Senate. He's smart, tough, and always moving forward."
Specter, who one year ago switched parties and became a Democrat, will face off in the Democratic primary against Rep. Joe Sestak; former Rep. Pat Toomey is the presumptive Republican Senate nominee.
Last week, Vice President Biden traveled to Pennsylvania and appeared alongside Specter at a rally, where he praised Specter for his research funding efforts, saying Specter "has done more to advance the frontiers of medical research" than any other elected American official.
A Franklin and Marshall College survey released March 24 indicates that a hypothetical race between Toomey and Specter is essentially tied, with Toomey's slight advantage falling within the poll's margin of error.