WASHINGTON — Anticipation of a close, exciting presidential election is mounting, so here's an election-night scenario that rivals the "hanging chad" madness of 2000 in Florida:

President Bush and Sen. John Kerry are neck and neck in the electoral vote count, with Kerry just slightly ahead but each just a few short of the magic number for victory: 270. Bush narrowly wins Colorado, which has nine electoral votes, and that puts him over the top.

But just as the networks are about to declare him the winner, word comes that Colorado voters have adopted little-noticed Amendment 36, scrapping the winner-take-all system — starting with this election.

The state's electoral votes are awarded by percentage of the popular vote. So instead of getting all nine votes, Bush gets five, Kerry gets four — and Kerry squeaks in, until the first lawsuit is filed at midnight and armies of lawyers parachute into Denver to battle over the referendum.

"If that amendment passes, and the candidates are in the 265-275 range of electoral votes, it could be a legal nightmare," predicted Michael Kanner, a political scientist at the University of Colorado at Boulder. "The courts could decide the election."

Even if the Colorado scenario doesn't unfold, what if — for the second time in a row — the winner of the electoral vote lost the popular vote? In 2000, Bush took 271 electoral votes, but Al Gore won 540,520 more popular votes.

Some analysts predict that that would finally focus attention on an Electoral College system that many see as an 18th-century relic.

"Given the intensity and passion of this year, the side that wins the popular vote and loses the electoral would go ballistic," said G. Terry Madonna, who directs the Center for Politics and Public Affairs at Franklin & Marshall College in Lancaster, Pa.

When Bush took the presidency in 2000 while losing the popular vote, it was the first time the Electoral College time bomb had blown up since 1888. Madonna thinks it's ticking again.

"I was shocked there was not a real debate about the Electoral College after 2000," he added. Many analysts say that debate didn't occur because everyone was preoccupied by the twists and turns of the Florida recount battle.

A 'dinosaur'?

Every four years, some voters are surprised to learn that they're electing the president only indirectly. The popular-vote winner in each state is entitled to electors, who meet in December to formally elect the president. Two states, Maine and Nebraska, already allocate one electoral vote to the winner in each congressional district, with two votes for the statewide winner.