Really?
To be blunt, these claims (which I don't think I've ever heard before) only make LBJ comparable to JFK if we ignore the fact there's a large volume of accounts of Kennedy having anonymous sex, but no such claims about Johnson. Maybe Johnson thought he had bested Kennedy in teh sexing of staffers and political hangers on, but that's not really JFK's entire field of play...
I was a little surprised that Dalek excerpted portions of letters that young Jack had written on football team trips, because that's solid evidence for him engaging in sexual activity with women whose names he never bothered learning, or at least quickly forgot. So it's now 'respectable' to assume he may never have changed this MO during his lifetime.
Also, is there even an 'other end of the spectrum' for JFK's extra-marital relationships--i.e. did he have any serious mistresses, from his own social caste, whom he might have considered settling into unofficial marriage with if he'd prematurely left politics, all while still officially married to Jackie? 'Cos biographers point to two women Johnson might have conceivably left Lady Bird for if he'd tanked in the 1948 senate election; Alice Glass and Helen Gahagan Douglas.
I've only ever read of one longterm-ish Kennedy girlfriend who was his social equal. Mary Pinchot Meyer.
I'll contribute to this with a response which it is important to note is intellectual and not emotionalist or protective: So what?
I grant you his prolific sexual escapades, as I did in the post you replied to. But I reiterate that men of Kennedy's era in power, and really any power (corporate, political, etc) were very much womanizers with a string of mistresses and dalliances and assorted extramarital affairs. Nelson Rockefeller died in what was most likely the midst of sex with a mistress for goodness sake. So as prolific as Kennedy was in his sexual escapades, in context it really isn't all that grand...at least compared to the populist notion of Kennedy having affairs as something no one else was doing. It's like Kennedy was playing football and was one of the best players. If there's no football team and he's alone and just tackling people to the ground in the hallway, that's one thing, but when there's an organized sport going on then it is another.
And the fact of the matter is, it doesn't amount to a hill of beans. The media of this era in the United States was not the scandal media we saw around the Watergate years and since then. They would have left his sexual dalliances alone. And the fact is that sex in Washington in that era is like Jenga: Kennedy may be doing it and it may harm him, but so are at least a large amount of the Senators and the Congressmen, if not most of them bodily capable of it. What is there to save them? That was a problem that even affected modern politics during the Clinton scandal. The GOP, with a Lee Atwater era fanaticism went after Clinton. That fanaticism also seemed to make them forget themselves because it then came out how all these Republicans crying foul on Clinton and damning him were themselves have extramarital affairs.
The concept of "Marilyn's Baby: The Ruin of Kennedy" is a very interesting one, I grant you, and I would myself read that timeline were someone to make it. However, it's easier said than done to have a sex scandal in America in the 1960s. Perhaps the only way to do it would be to have that "Marilyn's Baby" scenario. If certain biographies are true about her (and I'm not sure they are) she was an emotionally chaotic person with certain psychological issues who could have vindictively not left Kennedy alone and sought to bring him down...if the stories about his affair with her are true. That reminds me about the insane woman Charlie Chaplin was involved with in the 1950s who had a baby after he broke up with her, she claimed it was his, and destroyed him with negative publicity in the subsequent court proceedings. But I don't know if it's in Marilyn Monroe's character to do that, and I'd lean towards it not being so.
How Kennedy would deal with a bastard child, I'm honestly not too sure about. Pushing for and securing an abortion is a possibility, but I'm honestly not sure something as frankly wicked as that'd be would be what he would do. I frankly lean towards the idea that he'd pay the woman off and/or pay to support the child and mother for a number of years, all the while keeping it covered up. It could then come out years later, or could never come out.
On a quick note related to that last point, there have been people that came out and claimed that they were JFK's love child in recent years. These people have been debunked or are otherwise not very trustworthy. The one most likely man, who bears a strong resemblance to JFK, had a hair test which proved he was not JFK's son and subsequently blasted off about how there was a giant Texan conspiracy involving LBJ murdering Kennedy that he knew about, which makes it all the less likely he is JFK's love child since the LBJ conspiracy is the least believable.