Google will pick the first one it finds as the original. The others will be ignored. I do it a lot where I cut and paste then I go through and rewrite it so that it is different.
By cutting and pasting you are lowering the value of your link and you are preventing yourself from having multiple appearances on the front page. It doesn't really hurt the original, but it does not help it any at all. You could end up with the wrong site being identified as the original.