Sadly, last night's events will make a right-wing victory ever more likely. It doesn't really matter who the attacker was or the motive behind it. It will give rise to fear and anger, and as research including neurological brain scans have shown, those are the cornerstone emotions that drive conservatism and support for authoritarian "solutions". Not so coincidentally, conservative "solutions" tend to lead to outcomes that trigger even more fear, which is why it is so hard to get society to move away from that approach despite its clear failure as a solution.
Notwithstanding such research when a suicide bomb is exploded in the circumstances we experienced, people who are both to the right and left will experience and express anger and fear. A brain scan isn't required for that.
That is the point I was making. The fact that most people will have some degree of immediate fear and anger response is why most people, even those generally on the left, will shift to the right at least temporarily. That doesn't mean lifelong leftists will suddenly become staunch supporters of the conservative party. It means moderates and independents are more likely to vote in the short term to support those with aggressive intolerant rhetoric, and even some more clearly on the left will at least be less op-positional to policies they would normally strongly oppose. For example, it means that the majority of the US will support an illegal preemptive military attack on Iraq based on lies, despite all rational thought suggesting that the action will likely increase the actual threat of the thing that made them afraid (e.g., 9/11).
What the brain scans tell us is that there is a general association between fear, anger, and the kinds of responses and policies that conservatives favor, which typically entail supporting counter-violence for its own sake regardless of whether it deals with the threat, and authoritarian suppression of all things unfamiliar, uncommon, or that go against tradition.
What both the brain scans and all other relevant psychological data strongly suggest is that the main reason that some people generally favor conservative parties and their kinds of policies, no matter what recent events just occurred, is that they are highly prone to be fearful, anxious, and angry in their daily lives, even when the situation doesn't call for it. Teacher ratings of the chronic anxiousness of pre-school kids predicts their political conservatism 20 years later.
Actually the studies say that biology may be linked to political orientation for there is a lot more required.
OF course, all human behavior is multi-causal, but that doesn't mean you cannot significantly increase the prevalence of a behavior by altering one of those causes. Getting cancer is also multi-causal, but if you spray carcinogens on a population, the prevalence of cancer will go up, even if none of the other causal factors are themselves altered.
Also, while some of the biological differences tied to conservatism may be genetic (or otherwise "innate" due to In-utero factors), the brain scan differences do not directly speak to that. The scans are just a tool to measure low level neurological responses to various stimuli. How a person came to have those response tendencies is another matter, and it can include environmental influences, especially in early childhood that shaped their neurological wiring. For example, it could be that a child born into an environment that would trigger constant anxiety in almost anyone winds up with a brain that is prone to react to trigger anxiety in general, even when the situation doesn't call for it. That would tend to make the fear-based "attack the evil" rhetoric of both religious and GOP leaders seem more appealing and reasonable to this person.
Also, there are of course environmental effects that don't change the basic way the brain responds in general, but rather that instill assumptions and ideas that are more specific to political issues and that shape how one responds to an emotion like fear. For example, if you are taught that most people except for white Christians are evil and the cause of most bad things in the world, then when something happens that makes everyone afraid, you're first reaction will be to find which of the evil non-white or non-Christian groups need to be punished for it. Contrast that with a person who is taught that no one is inherently evil and that bad actions have no inherent relation to any "group" membership, and are the product of complex contingencies and sometimes random factors in a accidental godless world that no one is at fault for. When an event occurs that makes that person afraid, there first reaction is not to figure out what group to attack, but to figure out what complex circumstances brought it about and what response would actually be effective at making it less likely to happen. Thus, even a child born with a brain prone to high anxiety and fear can form a worldview that channels those fears into rational problem solving rather than the kind of blame-seeking violence to punish evil that essentially defines modern conservatism.
