As we all know, theism -belief in a specific, present god- is unjustified and silly.
Yet, arguments against theistic positions or religions don't necessarily apply to deism.
Deism relies on evidence drawn from nature - its creation by god, as opposed to supernatural revelations typical of religions. Furthermore, deists tend to believe that god does not currently interfere with what happens in the world.
Of course this different position also opens itself to a different set of potential supporting and opposing arguments.