Two years after the endless election that made "pregnant chad" a household phrase, Americans vote again today in a contest that could go long into the night -- and possibly much longer.

With the electorate evenly divided and control of Congress hinging on a handful of seats, Americans might have to wait days or even weeks before the final import of the midterm elections becomes clear.

Party strategists are facing the possibility, remote but not unthinkable, that the outcome might come down to special elections in Hawaii or Louisiana, delaying a decision until December or even January.

"Politically, it's still Nov. 7, 2000," the date of the last presidential vote, analyst William Schneider wrote in Washington's National Journal. "The two parties remain in stalemate. Control of both the House and the Senate may not be decided until well after Nov. 5, 2002."

In the Senate, Republicans and Democrats have 49 seats each, with one independent and one vacancy after the death of Democrat Paul Wellstone of Minnesota.

If that deadlock persists tonight, control of the upper house of Congress could be determined by the outcome in Louisiana.

Under Louisiana law, the leading Senate candidate must get at least 50 per cent of the vote to be considered the winner. If he or she gets less than that, the state will hold a special election on Dec. 7.

The Republicans are fielding three candidates today to try to keep Democratic incumbent Mary Landrieu from winning more than 50 per cent.

A runoff vote with a deadlocked Senate would turn Louisiana into a winner-take-all battleground like Florida in 2000. Money and manpower would pour into the state, and confusion would reign for weeks while the battle was fought.

Something similar could happen in Hawaii, were voters seem likely to elect a dead woman to the House of Representatives.

Democratic Representative Patsy Mink died Sept. 28, too late to remove her name from the ballot. If she wins posthumously, the state will hold a special election Jan. 4 choose a replacement.

That election would be significant if control of the House remains in the balance after tonight.

At present, the House has 223 Republicans, 208 Democrats, one independent who votes with the Democrats and three Democratic vacancies.

Most analysts expect the Republicans to hold onto their edge tonight, but if they do not and the House ends up deadlocked, Hawaii could make the difference.

Several other anomalies could cloud the outcome. In Missouri, Democrat Jean Carnahan is running for the Senate seat that she occupied after her husband Mel was killed in a plane crash just before the 2000 election.

If she loses to Republican Jim Talent, her stop-gap term would expire and Mr. Talent would be sworn in immediately, rather than in January with other senators.

That would return control of the Senate to the Republicans when it meets this month for a final lame-duck session. But control could jump back to the Democrats if their candidates make progress tonight and take office in January.

Other delays could take place in Georgia, where Senator Max Cleland will face a runoff if he collects less than 45 per cent of the vote, and in Oregon, where all ballots are mailed in, slowing the counting process.

And in one of the election's strangest twists, former Democratic congressman James Traficant of Ohio is running for his old seat from his prison cell. Mr. Traficant, who has declared himself an independent, was expelled from the House in July and is serving eight years for racketeering and bribery.

If he wins, the House would probably declare the seat vacant and hold another special election that could, again, make the difference in a closely divided chamber.

Voting irregularities could also push the count into overtime. In Florida, focus of the disputed 2000 vote, the Democrats' primary election for governor was a foul-up when touch-screen voting machines failed to work.

A repeat of that fiasco in Florida or other states could result in another tangle of lawsuits and court hearings that would keep the outcome in limbo.