Sorry, but you are way off in terms of proportions. Stalin remained in power by having his opponents murdered. Millions died under his rule and millions more were imprisoned for the most minor reasons, or by way of nothing more than coerced confessions. Hitler left office by his own hand after initiating the most deadly war in human history that, among other things, featured factory-style genocide. Both these leaders lead regimes in which terror, torture and fear were regular features. Dissent was not tolerated at all.
From what I read and from my experiences in the United States, Bush is hardly popular. There is active dissent against him, and he will be leaving office according to the law. Beyond that, the office of the president comes nowhere near possessing the powers that both Hitler and Stalin could wield. To confuse them is to either mock history or simply reveals a lack of understanding of the past.
One can criticize Bush for his actions and his considerable failing, but that should never be done by stooping to poor reasoning or shallow arguments that will, in the end, actually reduce the charges against Bush that one wishes to make.