It would be easy for a President Walker to retaliate. But I don’t think he will sink to that level.
It wouldn’t be retaliation, any more than Governor Palin’s dismissal of that bad cop was retaliation. I do admit that it would be spun as such.
As one who has lived through this nightmare (and it goes back further than Gov. Walker's terms...the GAB has interfered in state and local elections to benefit Dems for as long as it's been in existence), I would expect a President Walker not to "retaliate", but to definitely remedy the situation within the law in a similar way to his having neutered the unions' influence with Act 10 and such.