Senators John McCain and Barack Obama have officially entered the final stretch of the race for the White House. In the past month, Mr Obama has opened a significant lead in the polls, and former America correspondent for Dutch broadcaster RTL, Max Westerman, thinks he knows why.

For Mr Westerman, the demeanour of the candidates is key. "The impression that people get of candidates personality is at least as important but probably more important than what they actually say." To Mr Westerman, Mr Obama's cool persona has served him well during the campaign.

The Illinois senator never seems frustrated or out of sorts, a sharp contrast with his Republican rival who often exudes anger. According to Mr Westerman, there is a definite double standard at play in American politics.

"John McCain can somewhat afford to seem angry. A black person in the US cannot afford to appear angry when he wants to become president because then he is an angry black person. This is something Obama has to overcome, his skin-colour, and I think if anger were part of his personality, he could forget it."

Mr McCain lacks self-control
While Barack Obama has done well to avoid being typecast as a man harbouring racial anger, John McCain has not shown the same self-control. Referring to Mr McCain's debate performances, Mr Westerman claims that the Arizona senator did himself a disservice with his inability to contain his disdain for Obama.

"There seemed like there was pent up anger there. He was sort of like waiting to explode. I think this is one of the reasons Obama is probably going to be president."

Senator McCain has come under increased fire over the tenor of his campaign, which is seen by many as too negative. In recent weeks, the McCain-Palin campaign has attacked Barack Obama for his associations with 1960s radical Bill Ayers and the Association of Community Organizations for Reform Now (ACORN).

Negative attacks backfire
These types of negative attacks may work to decrease Mr Obama's favourability but they have also sullied Mr McCain's public image. Nevertheless, Max Westerman thinks that Mr
McCain does not have any other option.

"In his policy proposals [Mr McCain] is mostly George Bush and most Americans want to say farewell to the era of George Bush and his policies. So he has little choice but to go on a negative attack. Attack Obama's personality, his friends, his history, his lack of experience, those sort of things, because on policy he cannot win."

Though there are still two weeks till election day, Mr Westerman thinks that the race is, for all intents and purposes, over and that the way Mr Obama carries himself may be the x-factor.

"I think this is one of the reasons Obama is probably going to be president. It is his demeanour. It is the calm that he radiates and I think that's what Americans are looking for at this time."