Problem when copy-pasting from WORD to Blogger post editor

A blogger asked in the comments at Change blog background color and others: " I can't keep my font consistent throughout my posts...."

I suspect he is copy-pasting from MS WORD or some other word processor. When you prepare a document in WORD, it adds a lot of invisible formatting tags to the text that you type and when you copy-paste from WORD to the Blogger post editor, these formatting tags