I have no idea whether, in cases like the two you mention, we're talking about people who delight in fakery, people who lie out of some kind of compulsion or for some other kind of deep psychological reasons, or people who simply lie for an advantage and miscalculate.  But the question does remind me of two movies: first, Orson Welles' terrific celebration of hoaxes and cinematic evidence in F for Fake, and second, a film I happened to watch today, André Téchiné's The Girl on the Train (La fille du RER).

The latter film concerns a celebrated 2004 case in France, in which a girl falsely claimed to have been the victim of an anti-Semitic attack by youths who took her to be Jewish (at a time when real attacks were on the rise).  The movie seems to have disappointed some audiences because it doesn't reflect much (except indirectly) on the public spectacle caused by the hoax, or on anti-Semitism, but also because it doesn't take a determinate approach to motivation, not even by rejecting psychological accounts or endowing the story with obvious symbolic resonance.  Welles offers something like a metaphysics of fakery, Téchiné (I would say) a more moderate approach to the question, which takes account of social and psychological facts--he is very interested in the role of social moorings in modern society--but doesn't exactly psychologize.

In the case of exhibit 2, I wouldn't be so quick to see his actions as fraud. He might have significant guilt for his deferments and feel like he owes them to component them for what they went through, which he (cowardly he might feel) escaped.

I'm not claiming this to be the case with Blumenthal but when daily people who strongly oppose gay rights turn out to be gay, or people who strongly support marriage and are symbols of matrimony bliss turn out to have had multiple affairs, I find that people are all too quick to jump to the conclusion that they are a fraud. I think that many people feel guilty for being gay, for escaping the army, or committing adultery, and their guilt makes them all the move vocal and adamant against these things.

There are frauds, many of them, and sometimes these people do want to use and manipulate public opinion for their own good, as is probably the case with Tiger Woods, many supposed religious figures, etc. But some truly feel guilty for what they are and feel like it needs to be removed from the face of the earth, even if it includes themselves. I'm never sure how much they understand that it includes themselves, or do they compartmentalize so as not to see the two together.

As for your exhibit 1, there is a great movie by Steven Soderbergh, called The Informant, about such a guy, as well as Spielberg's Catch me if you can. The psychology of the faker is a complicated one. Do they want to reveal the lack of basis with which our system operates? I think that's why they are so scary. When one discovers that your brilliant Harvard graduate doctor actually never finished high school in Minnesota - it shakes how people organize the world.

I agree with you George about the complicated psychology of case 1. It reminded me of the book “Thomas the Impostor” by Cocteau. It is about an adolescent in WWI who happens to be at a certain place where they ask his name which is the same as a famous general’s. He answers that he’s his nephew, a lie that is very useful to him and to others. He enters his new identity which become his natural self, as he little by little seriously believes he IS the general’s nephew. The real general nephew’s (had there been one) would have had a hard time being as convincing as Thomas.

Here is how Cocteau lay this paradox:

“Il y des gens qui possèdent tout et ne peuvent le faire croire, des riches si pauvres et des nobles vulgaires, que l’incrédulité qu’il s suscitent finit par les rendre timides et leur donne une attitude suspecte.

Sur certaines femmes les plus belles perles deviennent fausses. En revanche, sur d’autres, les perles fausses paraissent véritables. De même, il existe des hommes qui inspirent une confiance aveugle et jouissent de privilèges auxquels ils ne peuvent prétendre. Guillaume Thomas était de cette race bienheureuse."

"There are people who possess everything and can't convince, rich so poor and noble so vulgar that the incredulity they arouse ends by rendering them timid and makes their attitude suspect.

On certain women the most beautiful pearls become false. In contrast, on others, false pearls seem realistic. Similarly, there exists men who inspire blind confidence and enjoy the use of  privileges which they can only pretend to possess. Guillaume Thomas was of this happy race."

Excellent movie recommendation too. Loved The informant.