HARRISBURG - Top state Republicans are throwing their political heft behind a plan to change the way Pennsylvania elects a president, setting the stage for a showdown this fall over whether the move would wipe out Pennsylvania's clout in national elections.

A brigade that reads like a who's who of legislative Republicans wants to do away with the winner-take-all system of apportioning the state's electoral votes and replace it with one that would do so by congressional district.

Senate Majority Leader Dominic Pileggi (R., Delaware), who is leading the charge, argues that the change will make the system fairer and more representative, and says that a bill could be voted on this fall, in time for the 2012 presidential election. Gov. Corbett has said he would support it.

Democrats counter that the proposed change is not only blatantly political - designed to give GOP candidates the edge - but also bad for Pennsylvania, as it will diminish the state's role in deciding who occupies the White House.

To that, Pileggi says: "This concept about clout and perceived importance is secondary to making sure that individual voters have a say in who the president is."

He added: "Everyone agrees Pennsylvania is one of the more diverse states in the union, and that diversity is not reflected in the current winner-takes-all sytsem."

The way it works now, the presidential and vice-presidential slate that wins the state gets all of the electoral votes.

In 2012, after redistricting, Pennsylvania will have 20 electoral votes and 18 congressional districts. Under Pileggi's proposal, each of the districts would elect one presidential elector; the other two would be apportioned on the basis of the popular vote.

Only two other states allocate electoral votes by congressional district, Maine and Nebraska.

Pileggi and other GOP leaders in the legislature, all of whom are expressing support for the effort, argue the proposed new system will more closely reflect the popular will of voters.

Critics call that crazy talk. They note that Pennsylvania would lose influence relative to other swing states that stay with a winner-take-all system.

"It's not a bad idea in concept, if all 50 states adopted it at the same time, but for Pennsylvania to do it by itself would be a disaster," said former Gov. Ed Rendell, the one-time chair of the Democratic National Committee. "Right now, in a general election, Pennsylvania is one of three states that basically decides the election."

Rendell called the move blatantly partisan, adding, "We'd love to get eight or nine electoral votes out of Texas, which we haven't won since LBJ."

Democrats have carried Pennsylvania in the last five presidential elections.

In 2008, President Obama carried the state by 620,000 votes. But under Pileggi's proposal, the then-Illinois senator would have netted only 11 of the state's electoral votes, with the rest going to Sen. John McCain, the Republican nominee.

Sen. Daylin Leach (D., Montgomery) noted that Pileggi was pushing this legislation even as congressional districts were being redrawn as part of the once-a-decade remapping process based on federal census figures.

Because congressional districts are reconfigured through legislation, the party that controls the legislature and the governor's office also controls the process, which good-government advocates say is rife with gerrymandering. Right now, both legislative chambers and the governor's office are controlled by the GOP.

"I think this an obscene desecration of our history and our heritage," said Leach. "We have fought on individual issues over the years, but both parties have respected the fundamental rules of our democracy and not used our power to change the rules to undermine or fix future elections."

Whether Pileggi's bill gets traction in the fall remains a big question mark. The Senate returns Monday and the House a week after that.

The legislature has a limited number of session days, in which it also wants to tackle several complex - and controversial - issues, including school vouchers and imposing a fee on natural-gas extraction from the Marcellus Shale.

Pileggi is calling the electoral-vote legislation a priority. His office disputes the notion that redistricting hasn't allowed for competitive elections in Pennsylvania, or that the proposal is a political power grab.

"Voters have shown an absolute willingness to split the ticket, and I think that trend will only increase," said Pileggi spokesman Erik Arneson.

Added Pileggi: "Each state decides how to choose its electors, and this is something we can do here in Pennsylvania for the benefit of Pennsylvanians. I think it's consistent with conversations about the disconnect between the popular vote and the Electoral College vote."

Contact staff writer Angela Couloumbis at 717-787-5934 or acouloumbis@phillynews.com.