The big question after every presidential debate has been, 'Who won?' A CNN-USA Today Gallup poll shows 53 per cent of the poll's 511 respondents thought Democratic challenger John Kerry came out on top.

Only 39 per cent felt U.S. President George Bush and did better in the third and final debate. The poll's margin of error was plus or minus 5 percentage points.

Kerry did even better when Gallup asked which candidate expressed himself clearly. On that, he beat Bush 60 per cent to 32 per cent.

Kerry and Bush tore through a number of domestic issues, from the economy and jobs, as well as social issues, such as same-sex marriage and abortion.

An ABC News poll, however, calls the debate a draw. Among 566 registered voters who watched the debate, 42 per cent called Kerry the winner, 41 per cent said Bush won; 14 per cent called it a tie. The poll's margin of error was plus or minus 4.5 percentage points.

The candidates have just a few weeks left of campaigning, and both Bush and Kerry plan to focus on states where polls show a close race.

During Wednesday's debate, Bush accused Kerry of making "a litany of complaints." He also attacked Kerry on his liberal voting record in the Senate, characterizing him as sitting on "the far left bank."

Kerry swung back on this issue. "Being lectured by the President on fiscal responsibility is a little bit like Tony Soprano talking to me about law and order in this country," Kerry said.

The controversial issue of same-sex marriage came up on Wednesday night, and brewed again Thursday. The candidates were asked if they thought homosexuality was genetic or a choice.

"I don't know. I just don't know," Bush said. However, he said he would protect the sanctity of marriage.

In his response, Kerry said he absolutely did think that people are born homosexual, and pointed to Vice-President Dick Cheney's daughter, Mary, who has publicly acknowledged she is a lesbian.

"She would tell you she is being who she was, she is being who she was born as," Kerry said. He also does not believe in same-sex marriage, but does advocate more rights for same-sex couples.

Cheney's wife, Lynne, later said she thought Kerry had crossed the line with that remark.

"Now, you know, I did have a chance to assess John Kerry once more and now the only thing I could conclude: This is not a good man," she said.

"Of course, I am speaking as a mom, and a pretty indignant mom. This is not a good man. What a cheap and tawdry political trick."

She did not explain what she meant.

Kerry's running mate, John Edwards, also brought up Cheney's daughter during the vice-presidential debate.

Edwards said he respected the Cheney's "for the fact that they're willing to talk about the fact that they have a gay daughter, the fact that they embrace her. It's a wonderful thing."

Cheney thanked him for the "kind words he said about my family and our daughter."

With files from The Associated Press