It's throwing darts at the president, and the president has a pretty thick hide on these matters. Look at who's working for Arnold these days; they have a pretty good barometer on how far you can push the president.
I think he needs to do it for two good reasons. It will invigorate the Republican base, which he sorely needs to do if he has any chance to win the special election. And it sends a positive message to the donor community that he's not going to cut and run.