Obama turns negative as McCain starts to challenge him in the polls
Updated on 21 August 2008
With his poll ratings on the decline Barack Obama has turned to negative advertising in an attempt to claw back supporters.
He has portrayed himself as being the "down to earth" presidential candidate, but his approach may be changing as his rival John McCain starts to pass him in some polls.
Now Senator Obama has seized on a remark by Senator McCain made only yesterday, that he doesn't know how many houses he owns.
