Can Obama keep his cool for second big debate?

Republican strategists hope voters will see the old 'straight-talk' John McCain when he meets Barack Obama for the second presidential debate tomorrow evening that will adopt a so-called town hall format with the moderator posing questions drawn from audience members and emails sent over the Internet.

Mr McCain, who prepared for the encounter near his home in Arizona, is due to arrive tonight in Nashville, Tennessee, 24 hours before the debate at Belmont University. Mr Obama rehearsed in North Carolina, a Republican-leaning state that he believes he might just win in November.

The onus tonight will be on Senator McCain whose path towards victory has narrowed considerably over recent days as voter anxiety over the economy deepens. He thrives in a town-hall setting and earlier invited Mr Obama to join him in ten such debates across the country. The Democrat declined.

"McCain has done so many of these over the years that it's probably going to be the best kind of forum he is going to be in," noted Terry Nelson, the Senator's former campaign manager. "It's a great opportunity for him and the campaign."

Aides to Mr Obama played the expectations game, predicting a masterly performance by the Republican. "Town halls have been the signature event of both of his presidential campaigns - he likes them, feels he does well at them," said campaign spokesman Jen Psaki.

Yet, the format may make it more difficult for Mr McCain to shed the gloves with Mr Obama as some of his supporters would like. While Sarah Palin almost boasted in her debate with Joe Biden last week that she would be ignoring the moderator by tacking off in any direction that suited her, that will be harder when the questions come from voters. Mr McCain can't be seen to insult or ignore them.

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Mr Obama will use the event to underline his message of recent days – that the Republicans are talking more about him than they are about the issues. He is certain to want to keep the topic as much as possible on the economy, the credit crisis and declining consumer confidence. Nor will he shy from offering unkind characterisations of his opponent, notably that Mr McCain is erratic in a time of crisis.

Most of the questions will come from a group of roughly one hundred undecided voters from the Nashville area pre-selected by the Gallup polling organisation. The moderator, Tom Brokaw of NBC, will meet them tomorrow afternoon before the debate to the help them hone what they want to ask. On stage, the candidates will have stools but will also be free to roam around.

The first debate, in Mississippi, was also meant to favour Mr McCain because its main theme was foreign policy. But most observers gave it to Mr Obama on points. The Democrat was poised and courteous. Some viewers were turned off by Mr McCain's refusal to look the Democrat in the eye.

If Republicans expect Mr McCain to deliver a punch tonight hard enough to change to the course of the race they may be disappointed. "The key thing will be whether McCain can get under Obama's skin this time. Obama was cool, maybe too cool, in the first debate," said Linda Fowler of Dartmouth College. "Obama looked presidential. If he continues to look like he can handle tough situations, he'll come out stronger than ever."