With Democrats in Washington preparing to decide whether to punish U.S. Sen. Joe Liberman (I-Conn.) for his full-throated support of John McCain, Pennsylvania's Democratic Senator is unsure whether he will vote to strip Lieberman of his committee leadership.

U.S. Sen. Bob Casey, an early and fervent supporter of Barack Obama, told The Hill that while he was frustrated with Lieberman, retaliation might not be the best idea.

"I was frustrated when I listened to him to undermine Barack Obama, but we're going to have to think carefully on how that frustration plays out in the interests of getting things done," Casey said.