Of all the characters I thought were most comfortable in the 1950's, it was Peter and Trudy. However, their reaction to Kennedy at first seemed surprising, given Pete's want to climb the corporate ladder, he seemed all to willing to want to mold himself into another Roger Sterling.

However - if we recall:

A) he was one of the only characters to show disgust at Roger Sterling's black-face;

B) He was most open to trying to market to African Americans, and not necessarily in a sinister manner;

C) Pete has always struggled at work. The "hair" who won over him was a natural at the client relations (well – that seemed to be what we observed anyways). Pete was the one threatened by the competition, and Pete has always seemed to be one nervous breakdown away as he struggled to prove himself.

D) Unlike Don and Roger, Pete has never been successful at the philandering side of the Mad Men world, which seems to require a kind of confidence and machismo that exists only to either those born of privilege (Sterling) or a master of deception (Don/Dick). Pete is neither, and life and work has always seemed like a struggle with him.

However – was Pete projecting his own issues, and therefore, seemed more sympathetic to the Kennedy assassination? He mentioned that the Sterlings were happy, and therefore were at east holding a wedding so soon after the assassination. Was Pete’s hope for change a sudden reaction to his loss of control over his career? Could it be that Pete and Trudy, so ready to go full-steam ahead at Sterling Cooper and live the in the 1950’s (they danced a swell Charleston), saw their dreams crushed by Sterling Cooper, and suddenly, were like so many who voted for Kennedy, were on the outside looking in at this rarified WASP world?

Pete wants to be more to Sterling Cooper (to everyone, really) than his family name. You're right, he's been portrayed as more forward-thinking than one might expect from his character right off the bat. But he's ready for a change from the 'old guard'. Scenes with his father when he asked for money, the telling of his family story when he and Trudy were just buying their apartment...he wants to cast it off, badly.

The shot of him in the black turtleneck was interesting...

I'd have to look again, but wasn't Pete suggesting that Roger Sterling would be "happy" BECAUSE JFK was shot? A brutal remark, but people made them.

The complex Pete Campbell has always had a certain socio-political foresight to go with his weaselhood. In Season One, he talked positively of Elvis as a societal influence, and was slapped down by Old Man Cooper for his youthful ignorance.

And this season, he had the foresight about the black consumer(one step forward and one step back given his grilling of the elevator operator on the subject.)

Whatever the linkage of Pete's bitterness about his job demotion to the JFK killing, Pete was the mouthpiece for the younger generation's heartbreak over JFK getting killed: the handsome young President was gone, to be replaced by a return to the status quo, the cagey ol' Lyndon Johnson. "Nobody elected Johnson," Pete said, further underlining how assassination could change the entire "deal" on a Presidential administration. Later, watching the replay of the Oswald killing, Pete advances the pragmatic entry-point to conspiracy theory: "There's no security. He's just exposed. Now we won't get a trial. They just turned him over to the mob." (And, it was suggested in real life, to The Mob -- Jack Ruby had mob connections.)

Its too bad that Pete raped that au pair this season and retains his Daffy Duck-ish capacity for whiny envy and failure...he's coming along as one of the characters most prepared to change with the times.

Oh, well. Maybe he'll come out OK. It wasn't rape-rape. Ha.