How do I set default text to bold?

My client creates notices where all text is bold. I have figured out how to change the config.contentCSS to change the default text to font-weight:bold;, but this is not the same as pressing the bold toolbar button which uses tags. I changed the CSS and showed the client with the bold button removed (since it is no longer needed since all text is bolded via CSS), but they insist that they need the bold button there, in the off chance that they don't want something bold. See my predicament? So is there a way to force all inserted by CKEditor to be or alternatively to for the bold button to only affect the font-weight of an element?