Forum Post: What is the purpose of re-election campaigns?

I read in the news that Obama's main focus from now on will be on his re-election campaign rather than governing.

Can anyone explain why this campaign is needed, shouldn't his, or any other politician's voting record be enough to draw their political portrait?

To me a re-election campaign is when the corrupt politicians pocket their "donation" bribe money promised earlier by special interest groups for duping their constituents on critical voting matters...