"I have a lot of respect for the majority leader, but this is the wrong policy at the wrong time," Casey said in an interview. "That we wouldn't speak with one voice, the way we always have, would put us at a disadvantage."
Casey asked Pileggi to make sure the Electoral College proposal, Senate Bill 538, was reviewed thoroughly in hearings before it was put to a vote.
The majority leader has 12 cosponsors for the legislation. His proposal would split the state's electoral votes based on the percentage of the popular vote each presidential candidate receives.
Under Pileggi's proposed formula, President Obama, who carried Pennsylvania on Nov. 6 with 52 percent of the popular vote to 47 percent for Republican Mitt Romney, would have received 12 of the state's electoral votes to Romney's eight.
Pileggi's spokesman said the proposal was not on a front burner. "No time frame has been established for the bill, but if anything happens, the first step would be a public hearing," Erik Arneson said.
Casey was not reassured. "Sometimes in Harrisburg, even things that are on the back burner can move fast."
He noted that although the state has gone blue in recent decades, the GOP carried Pennsylvania in three straight presidential elections from 1980 to 1988.
"Republicans should remember, this state has a political pendulum that goes back and forth," Casey said, "and history tells us it will swing back."
Contact Thomas Fitzgerald at 215-854-2718 or firstname.lastname@example.org, or follow on Twitter @tomfitzgerald. Read his blog, "The Big Tent," at www.philly.com/BigTent.