Perhaps the Bush impersonator has to reclaim his liberal 'cred" in order to work in "the business." Does Steve Bridges appear on Leno or such shows? He might have a lot of 'splainin' to do, for cooperating in a skit with the real President Bush.
"Are you now or have you ever been a member of the Republican party??!!!"
According to the news articles about his appearance with Bush at the Correspondents dinner he does the Bush stuff regularly on Leno. They didn't mention if that was the only place he did that particular bit.
At the end of the act Bush introduced him and claimed that Bridges had done most of the debates with Kerry. That was perhaps the funniest line all night.