If you think you can win that fight after Rove / Libby (maybe higher up) are indicted, I think you are mistaken.
It all depends on how the leadership reacts. Maybe in such a circumstance, Bush might find it more advantageous to slip more into the background after nominating Brown and let a Senator like Brownback do the heavy lifting of explaining to the public why the Democrats are being so hypocritical on this. This is something that can easily resonate with the public, so all it comes down to is making the right arguments, and if necessary, getting the right people to make the arguments.
If Bush wants to start turning the tide in the PR fight, he might want to try doing the right thing here and get his base solidly on board with him. Because right now, he has almost nobody solidly on board with him, and that's never an enviable position to be in.