It isn’t until the end of the fourth paragraph that we see the note:
It is unclear if Bush is in the process of responding to that message or wrote it himself.
Focus on that line.
I downloaded the photo and resized it to 800 pixels wide by 458 pixels tall. It is very clear that the comment “I think I may need a bathroom break?” was written in block letters by a person other than the one responding to it in this photo. The hand in the photo, if it is President Bush’s, is clearly writing not only in script, but at a slightly different size, with a different amount of force than the person who wrote the block comment. I imagine at trained handwriting analyst could note far more inconsistencies between the two areas of text.
Oh, come on, Yankee, do I have to spell it out? Because they haaaaaate President Bush and they are stuck in the behavior patterns of spiteful, malicious children who have never gotten past making fun of anyone who doesn’t sit at their lunch table!