What was the point of the New Year's Eve party in Havana with all the judges and politicians? Ostensibly Michael, Roth and other industrialists were there to bribe Batista and get something for their businesses in return. In the case of Mike and Roth it was to get control of the casinos, and also to kill each other. What was the point in having all those political types there? In fact wouldn't Geary have known there might be an upcoming investigation by his own committee on Michael?
The whole point of the blackmailing of Geary was that he was no clean family man, but someone who dealt with prostitutes, yet in Havana there he is with all the judges and other pols telling Fredo he wants the red headed Yolanda. Other than to drive the plot to get them into the Superman show, why were these guys even there?

DT, reagrding many events we don't know how much time elapses between them. Geary and other US politicians were the same then as they are now: they accept favors that sometimes involve travel to what are generally considered vacation resorts. Those Havana meetings were heavily framed as business oriented. So, the presence there of US politicians could be disguised.

Clearly it was a "junket" for the pols, but I was curious as to why they would go out of their way to hang out with the Corleones, and why Geary would e so openly affectionate with Yolanda.

Well DT, even in III we have Michael quite publically buying into a comglomerate despite decades of well known organized crime activity. So, it's not surprising that Puzo and FFC would have politicians publically involved with him in II after only a decade of organized crime activity.

As for Geary, we now have a married US House Representative who absented himself from his Governor's office to have an affair in South America. So, it's not surprising that Geary got away with what he did back then with little or no publicity.

You suppose Geary floated the story that he was hiking in the Sierra Nevada mountains?

In addition to the ever-present directorial license, I think the reason for the judges and politicos in Havana is that Michael summoned them. Probably he was paying them off, and he thought he had Geary's coglioni in his pocket after the brothel murder. So, he might have been flexing his political muscle by summoning them there. He might also have been establishng an alibi for himself. Even though Fredo hadn't made his fatal gaffe yet, Michael knew that he had to kill Roth before Roth killed him-- "Hyman Roth will never see the New Year." He was creating a gilt-edged coterie of high-powered people to attest that he was nowhere near Roth when Roth was to have been murdered by the bodyguard.

I like the alibi angle TB

You all are looking at it the wrong way. You have to look at it from the politician's point of view not the Corleone's. The politician's are there to buy favor's and make themselves noticed just like the Corleone's. You'd be surprised how many politician's get elected with mafia help.