Supporters of Rudolph W. Giuliani and of Senator Hillary Rodham Clinton are embroiled in their first major affray of the political season over a ballot initiative on presidential electoral votes some 2,500 miles from the pancake houses of Skaneateles, N.Y., and the fire stations of Queens.

The fight could be a telling prelude to the 2008 presidential contest, with the political instincts and strategies long employed by Mr. Giuliani, a Republican, and Mrs. Clinton, a Democrat, cast in sharp relief. The battle has reflected their political set-to in 2000, when they squared off briefly over a United States Senate seat in New York, and could foreshadow how the game will be played should they become their parties’ nominees.

The proposed measure here would ask voters to apportion electoral votes by Congressional district, potentially giving the Republican nominee in 2008 some 20 of the state’s 55 votes — the rough equivalent of winning Illinois or Pennsylvania — in this otherwise reliably Democratic state.

Such a change could amount to a seismic shift in the nation’s electoral dynamics, potentially springboarding a Republican into the White House, and the possibility has animated hopeful Republicans and fearful Democrats.

Started by a Republican lawyer in California, the measure has been driven almost entirely by people who are associated with or have given money to Mr. Giuliani’s presidential campaign.

The effort to kill the initiative — executed with a swift fierceness almost unheard of against an initiative in such an early stage — has been led by a bevy of Clinton supporters, including a former Clinton White House official, prominent elected Democratic supporters and one of Mrs. Clinton’s most prolific fund-raisers.

“Clinton’s people have taken the Bush doctrine of pre-emptive military strikes against hostile nations and applied it to domestic campaigns,” said Bruce E. Cain, director of the Institute of Governmental Studies at the University of California, Berkeley. “As for Giuliani, he was trying to fight under the radar, and it must be clear to him now that that will not work with Hillary.”

[ . . . ] Mr. Lehane, whose thumbs are no doubt sore from constant BlackBerry messages to reporters, has raised endless questions about the source of financing on the other side. The group initiated a complaint with the Federal Election Commission questioning the ties of the measure’s supporters to Mr. Giuliani, largely because Mr. Singer did not immediately reveal himself to be the donor behind the effort. The Democratic group even dug up a charges from a 17-year-old lawsuit against one official backing the initiative, a charge involving the biting of a woman’s bottom, and disseminated that as well.

Amid the accusations and pitfalls, Thomas Hiltachk, the lawyer who drafted the initiative, walked away from the effort, citing ethical concerns about the way the money was raised. His resignation has left the initiative’s future in serious jeopardy, and many Republican consultants around the state are advising their clients and friends to steer clear of the effort, suggesting it will be challenged on constitutional grounds if it passes.

Still, some Republicans are seeing a missed opportunity, worried that the Giuliani loyalists are being outmaneuvered by the Clinton loyalists.

“Lehane did a good job of rallying the entire Democratic establishment to be vocal and aggressively against this,” said Scott Reed, a veteran Republican strategist who ran Bob Dole’s 1996 presidential campaign. “And the gang that couldn’t shoot straight proved their worth.”