US presidential election enters slug-out stage

Now that "churchless Christian" Barack Obama has certainly clinched nomination as the official presidential candidate for the Democratic Party, the battle line is drawn and he is confronting one-to-one John McCain from the Republican Party. Since the American Congress has been in the firm control of the Democrats, would US voters opt for a check-and-balance to ensure that powers won't be too concentrated ? Or, would they go for change regardless of its impact on the balance ?

Worldviews of McCain, Obama in perspective