Debate crucial as US race turns ugly

By Jonathan Beale
BBC News, Nashville

John McCain needs to do more than simply avoid slipping up

The tone of the campaign has got nastier.

John McCain's running mate Sarah Palin has said the "gloves are off" and to prove it she has accused Barack Obama of associating with "terrorists", a reference to his rather loose links to Bill Ayers, who decades ago was a member of the militant Weather Underground group.

The Obama campaign has hit back with adverts calling the Arizona senator "erratic in a crisis and out of touch on the economy" and highlighting his role in another decades-old scandal, "the Keating Five".

The dredging-up of the past by both campaigns is clearly designed to hurt.

But are the two candidates prepared to continue the mud-slinging when they go head to head in Nashville for the second debate?

In the last debate, some commentators believe that John McCain suffered because he did not show enough respect to his rival

The answer is probably not. In American politics, it seems that it is okay to allow surrogates to hurl insults but it becomes far less appealing to the electorate when the two protagonists get down and dirty.

In his debate with Walter Mondale, Ronald Reagan scored points by saying to his rival "There you go again…" with a smile on his face.

This is not a competition to see how low you can go - it turns most voters off.

Voters first

The polls suggest that Barack Obama won the last debate even though a fair number in the media - including yours truly - believed that John McCain got the better of his rival on foreign affairs.

The debate in Nashville is due to take place in a more intimate setting

I now realise that it is a mistake to judge these debates as you would, say, a UK prime minister's question time.

Presidential debates are not a cockpit of confrontation.

The goal is not to bait the other side or engage in purely political point-scoring. It is more important to engage with the electorate watching at home.

In the last debate, some commentators believe that Senator McCain suffered because he did not show enough respect to his rival.

He talked about him as if he was not there. Senator Obama may have won some sympathy by addressing the camera directly at the start, a trick picked up by Sarah Palin in the vice-presidential debate.

It is more important to show empathy with the electorate than political aggression.

The format of this second debate may help the candidates. It is billed as a "Town Hall" meeting where members of the audience - all undecided voters screened by the polling company Gallup - get to ask the questions on their mind.

It is also the first-ever presidential debate in which members of the public have been able to submit questions via the internet.

But do not get too excited - it is all being filtered through a moderator, NBC veteran Tom Brokaw, who will ensure a sense of order and decorum.

Pressure on McCain

The state of the economy is the issue that once again is likely to be at the forefront of the electorate's mind and will undoubtedly dominate the questions being fielded.

John McCain comes to Nashville from a round of campaigning in New Mexico

Again, judging by the polls, that will make it harder for John McCain.

How can he distance himself from a deeply unpopular Republican administration, which is largely getting blamed?

How can he appear on top of the issue when earlier in the campaign he admitted that he was not across the subject as much as he should be?

The mind games have started even before the two candidates arrive in Nashville.

The Obama campaign is raising expectations for Mr McCain, suggesting the "Town Hall" format will favour him, that it is something he is more comfortable with and used to doing.

They did the same in the last debate by reminding the media that foreign affairs was Mr McCain's natural turf.

It is an age-old political trick - talk up your rival and, when it is all over, you can appear surprised that your guy did so well.

There is no doubt that Mr McCain has been putting in the practice. Unlike the last debate, where he seemed to have set aside little time for preparation, this time he has spent the weekend rehearsing at his ranch in Arizona.

He knows he needs to change the trajectory of the race and this may be one of his last opportunities.

Mr Obama is racing ahead in the polls. Nationally, he has built up a six-point lead and, more importantly, appears to be gaining ground in a number of key battleground states.

Conventional wisdom says that the most important goal of each debate is not to slip up, that it is more about staying in the race than dramatically altering its course.

That may be true for Mr Obama, who now appears to have a comfortable cushion, but John McCain needs to do more than that.

Hence the change in strategy and his campaign's emphasis on the personal.

The trick for Mr McCain is to raise questions about Mr Obama's past and his judgement without appearing mean-spirited.

If he does the latter, he will have fallen into the trap that the Obama campaign has set.

Watch the second US presidential debate live from Nashville, Tennessee from 0100 GMT, with full analysis, running commentary and voter reaction.