Barack Obama's selection of a running mate, the stagecraft of his nominating convention and Republican rival John McCain's ad to stir up Democratic trouble all have a target.

White America.

The candidates are going after those white working-class voters who are still up for grabs in their tightly fought campaign. From polls the candidates know many of these voters are sceptical of the first-term Senator who will become the first black presidential nominee of a major party.

Obama's convention is aimed to tell them that he shares their values and has a truly American story, even if he grew up in exotic locales like Hawaii and Indonesia.

"You'll find out, 'He's pretty much like us,"' Obama told a white crowd at a barbecue Sunday in Eau Claire, Wisconsin.

McCain sees where Obama is headed and is trying to cut him off at the pass. Many of these white working-class voters were so-called Hillary Democrats because of their support for Hillary Rodham Clinton in the Democratic primary.

McCain tried to stir them up with a new television ad that repeated her criticisms of Obama and suggests that's why he wouldn't pick her as his running mate.

"The truth hurt, and Obama didn't like it," the announcer intoned. The ad follows up on McCain's series of commercials that painted Obama as the "world's biggest celebrity" — in other words, not like average Americans.

Obama receives the support of just one in two voters who backed Hillary Rodham Clinton in the primaries, according to an NBC/Wall St. Journal poll out this week. Those are numbers both campaigns are keenly aware of.

Obama's choice of Sen. Joe Biden was aimed at helping make inroads. In his announcement on Saturday that Biden was his running mate, Obama stressed that Biden is a Catholic and native of blue-collar Scranton, Pennsylvania, who takes the train home to his Delaware home every night from Washington DC and "whose heart and values are rooted firmly in the middle class.".

"This working-class kid from Scranton and Wilmington has always been a friend to the underdog, and all who seek a safer and more prosperous America to live their dreams and raise their families," Obama said.

The convention will have a special emphasis on reaching women, including repeated recognition of the 88th anniversary of the women's right to vote tonight. That's the night Clinton will speak, along with other female Democratic Senators.

Michelle Obama, the candidate's wife, will have a dual role of reaching out to women — she's headlining an economic round-table with female governor's today — and showing America her husband's softer, family side.

Obama told those at the barbecue that his wife's speech will help voters learn more about them.

"You'll have a sense of who she is and what our values are, and how we're raising our kids," he said. "And I think what you'll conclude is, 'He's sort of like us. He comes from a middle-class background. He went to school on scholarships. He had to pay off student loans. He and his wife had to worry about child care. They had to figure out how to start a college fund for their kids'." – Associated Press