Quote from kjkent1:
You want to sue everyone who voted for Bush? That's a novel lawsuit. Nevertheless, you are miscomprehending a legal tort theory that is completely inapplicable. Just because it's called "contributory" negligence, doesn't mean that you can advance the theory against anyone who has contributed to the negligence. Contributory negligence is a theory only available to a defendant to prevent a plaintiff from obtaining compensation for damages that were caused by the plaintiff's own failure to use due care. PERIOD!
What you are attempting to argue is called, "equitable contribution," i.e., the theory that a person should fairly contribute to satisfying a judgment for damages on grounds that they have some responsibility, even though they cannot be held legally liable. This is exactly the situation that you are describing. The President is immune from civil liability, however he is an agent of the electorate who voted for him, and "but for," the electorate's negligence, President Bush would not have been elected.
The question, then, is whether the electorate was negligent in voting for Bush. Negligent requires an existing duty of care, the breach of that duty, and proof that the defendant is the actual and proximate cause of the plaintiff's injuries.
The electorate has a fundamental right to vote, however, it has no legal duty to vote. Once a person chooses to vote, it is possible that they may have a duty to use due care in their decision. If you could prove that a voter failed to educate themselves in any meaningful way prior to casting a vote, then you could possibly show that they violated their duty to vote responsibly. Unfortunately, you cannot do this, because no person can be forced to state their choice in an election. So, you have a "proof of facts" problem. You cannot prove your case, because your witness cannot be compelled to testify, and that would end the lawsuit.
But, let's say that you could get voluntary testimony from every person who voted for Bush, now how will you prove, that "but for" the electorates' breach, the hurricane would not have occurred? Hurricanes as big as Katrina have been recorded in occurred in the past, before the idea of global warming was ever contemplated. So, here the evidence fails again. There is not a preponderance of evidence to demonstrate that global warming is the direct, or even a clear and convincing cause of hurricane Katrina.
Judgment for the defendant (Bush and the Republicans).