Brush and Bush? You provided too many hints. The despicable characteristics you are referring to are mostly invented by the left, however. The actual ones are minor and go unrecognized by them. Namely, being too liberal, and thinking he can appease them by acting like one. That only fuels their hatred.
Very good, although Shrub & Bush were actually what I was thinking ... however your mention of ‘brush’ did bring this puzzle to mind (for whatever strange reason ;)
Agreed about the “despicable” nature of GWB being a hackneyed & overblown excuse by the Libs, used here simply as an over-the-top hint.