When your liberal friends (hopefully you have none) or the Legacy Media report on all the horrible right wing nuts comparing Obama to Hitler and how hateful they are, you need only steel yourself against their attacks by reminding them of the wonderful way the Left treated George W. Bush the last 8 years.
Of course, you don't need to do the actual research, our friends at Zombietime have done it for you.
Just read the article, check out the photographic evidence, and enjoy the many links.
Additionally, anti-Bush protestors frequently advocated bodily harm (usually in the form of death) to Bush. Don't remember? Read this.
For the last 8 years, comparisons of Bush to Hitler were so routine, the term Bushitler was even copyrighted. Maybe.