re: Well, if you insist...
The one the Democrats use is also preferred by the Bureau of Statistics for being the most accurate. Using any other would just be trying to cherry pick the results by changing the system in mid stream. Of course cherry picking is a Bush specialty so this is no surprise.
There's also another system in which all unemployed are lazy bums and are presumed to be not really looking for work. Under this criteria Bush has maintained full employment, quite an impressive result.