No....but she wasn't robbed.
When you are talking about an assasination attempt (which is what it was) it is almost always about their beliefs. There may be an occasional one who will do it to be famous (Mark Chapman, John Hinkley come to mind) but they are few.
As for your comparison between the shooter and other assasins I would reply that ALL assasins are crazy.
Bottom line? He's alive so let's just see what he says.
We've already heard what he had to say, and it was insane. I don't think you can lump him and people like him into "about their beliefs" when the beliefs in question are utterly random and insane.
As for "almost always", try again. Let's review some assassinations and attempted assassinations in America, shall we?
Charles Guiteau - considered insane by everyone who knew him. Believed himself responsible for Garfield's election to the Presidency, and assassinated him because he thought Garfield was "ungrateful" because he wouldn't appoint him ambassador to France.
Richard Lawrence - tried to assassinate Andrew Jackson and was actually found not guilty by reason of insanity and confined to a mental institution.
John F. Schrank - tried to assassinate Theodore Roosevelt because, he said, President McKinley's ghost told him to do it. Was found not guilty by reason of insanity and and institutionalized.
Guiseppe Zangara - tried to assassinate Franklin D. Roosevelt and managed to kill the mayor of Chicago and shot four other people besides. His reason? He believed the President was causing his physical ailments supernaturally.
Richard Paul Pavlick - plotted to assassinate JFK in a suicide bombing, but backed off in his attempt because Kennedy's wife and child were with him. While he DID have problems with Kennedy's actual politics, he seems to have objected even more Kennedy being Catholic. He spent the rest of his life in and out of mental institutions, which is why I include him.
Samuel Joseph Byck - tried to hijack a plane to fly into the White House in an attempt to kill Richard Nixon. His reason? He blamed Nixon for being turned down for a business loan by the Small Business Administration. He suffered from severe depression and had spent time in a psychiatric ward.
Lynette "Squeaky" Fromme and Sarah Jane Moore - both tried to assassinate Gerald Ford within days of each other, and both members of the Manson family. 'Nuff said.
John Hinckley Jr. - tried to assassinate Ronald Reagan in order to impress a girl. Confined to a mental institution.
Frank Eugene Corder - tried to fly a Cessna into the White House to kill Bill Clinton, but friends say he had no problems with Clinton that they were aware of. Since Corder died in the attempt, no one knows for sure what his motive was, but those who knew him are convinced he wanted the attention.
And that's just the
Presidents killed or attacked by crazy people or at least for reasons other than their political positions. This doesn't even count the ones who did it for political reasons such as wanting to bring down the government just in general, which has nothing to do with the personal political positions of the target.
Completely aside from the probability that ANYONE who resorts to assassination is probably not the cover model for
Sanity Fair, it is obvious that, far from being rare, true insanity as a motive for attacks on politicians is quite common.