St Paul, Minn. ? They embody four uniquely American stories. They offer messages of transformation with two distinct world views. They pursue one goal.

Republican John McCain and Democrat Barack Obama and their respective running mates, Sarah Palin and Joe Biden, begin the final eight weeks of their historic and remarkably close presidential contest ready to rewrite national politics.

Race, gender and age barriers are at stake. A shifting political landscape will take the fight to previously ignored states. Advertising will suffocate the airwaves. Debates could be as decisive as the final Carter-Reagan debate of 1980. More money will be spent by the hour than ever before.

Armed with a bigger bankroll and a partisan Democratic advantage, Obama is competing in more states than John Kerry did in 2004, including typically Republican states like Virginia and North Carolina.

Soon, strategists predict, the number of states in play will narrow to nine or 10, resembling past elections with Virginia the new battleground in the mix.

As election day closes in, they say, McCain needs to shore up his position in previous Republican states and hope the only states left in play are Ohio, Pennsylvania and Michigan.

“Whoever wins two out of those three will probably win the election,” said Scott Reed, a Republican strategist who managed Bob Dole’s 1996 campaign and is close to the McCain camp.

Obama and McCain march into the fall campaign with their parties newly unified – tasks they accomplished by each reaching out to a female political figure. Obama joined hands with former rival Hillary Clinton and sealed the deal with many of her supporters. But McCain’s stunning selection of Palin has the potential to change the game.

Obama sits atop a mountain of advantages. President Bush and the Republican Party remain highly unpopular, Democrats have displayed greater intensity, Obama has expanded the electorate, and he has set records for political money.

McCain, however, has managed to remain far more popular than his party or his president. Independent voters and even some Democrats remain unsure about Obama, either because of his race or his rapid rise from obscurity.

And while Obama’s election would represent a monumental milestone for the nation by putting the first black man in the White House, Palin gives voters a chance to make history, too, by electing the first woman as vice president.

Both candidates have targeted 11 states with advertising this week. They are Colorado, Florida, Iowa, Missouri, North Carolina, New Hampshire, New Mexico, Nevada, Pennsylvania, Virginia and Wisconsin. McCain and the Republican National Committee also are up with an ad in Minnesota.

Obama, however, has expanded the field for now, placing ads in Indiana, Michigan, Montana, and North Dakota.

Five battlegrounds – North Carolina, Pennsylvania, Virginia, Missouri and Michigan – begin distributing absentee ballots between Sept. 19 and Sept. 23.