Look at Obama’s only re-election campaigns in 1998 and 2002.
In 1998 he ran unopposed in the Democratic primary and won the general election 89-11. Basically, unopposed.
In 2002 he ran unopposed in both the primary and general election.
http://en.wikipedia.org/wiki/Illinois_Senate_elections_of_Barack_Obama
So he - and more importantly his team - have never had to really run a true ‘re-election’ campaign. Shows, doesn’t it.
Heck, look at his election campaigns:
In the March 19, 1996 primary election, Obama, running unopposed on the ballot.
In the November 5, 1996 general election, he ran against perennial unsuccessful candidate David Whitehead and first-time candidate Rosette Caldwell Peyton.
In the March 16, 2004 Senate primary, Obama ran against six other candidates, with only one viable candidate, Daniel Hynes, and a well funded first time candidate Blair Hull. If had been a two man race between Obama and Hynes, it may have turned out different.
Then of course, he had the Republican candidate, Jack Ryan, destroyed, and got a speaking role at the DNC.
Finally, he got to run against the hapless John McCain during a period of economic collapse and the least popular lame-duck incumbent since Johnson.
The only time he took on a real candidate in a competitive race was his 2000 primary challenge to Representative Bobby Rush, and he was crushed.