Remember also that he thought at that point that Michael was cooked. Its low risk to extricate himself but the reason (he was either blackmailed into stepping down or to avoid implicating himself by defending Michael or simply to stick it to Michael without upsetting his Italian constituents) is less important than creating the drama of a further betrayal for Michael.

It's not that they couldn't kill him, they could have easily. The point is he was worth much more to them alive than dead. THe prostitute scene is analogous to the horse's head scene in One, except they've upped the ante.

No, they couldn't just kill him. He was a friggin US Senator. Good thing for the mafia you were never a boss, lol.

It's not that they couldn't kill him, they could have easily. The point is he was worth much more to them alive than dead. THe prostitute scene is analogous to the horse's head scene in One, except they've upped the ante.

Remember the opening scene when Geary and Michael talked in private? Remember the smug tone Geary used in speaking towards Michael and about Michael's family?
Now do you remember the brothel scene later on? Where Geary supposedly 'passed out' and 'killed' the prostitute he was with?
The two are connected. They couldn't just 'whack' the guy for his brash attitude, he's a US Senator, that would bring way too much heat. Instead they blackmailed him. Not only did he commit adultery with a prostitute (which was a far bigger sin for politicians in the 50s than it is today), but she was also found slaughtered in bed with him (he didn't actually kill her, though). They got him hook, line and sinker.
Thus you have the reason he excused himself from the Committee. The Corleone family had dirt on him; major dirt. So he was blackmailed into stepping down.

Pat Geary was loosely based on Pat McCarran, who was a US Senator from Nevada from 1933 to 1954.
Never hate your enemies. It affects your judgment.
-Michael Corleone

It was based on an actual event by an actual senator during the Kefauer (sp?) crime hearings of the late 50's. I don't have time to look up the specifics, but there are several nods to actual mob history in the two films.

I don't think it was so outrageous back in the 50s. Part of michaels defense is that he was being persecuted because he is Italian. Gearys speech just reminded the public of that. To your point though, the chairman did roll his eyes at Geary ha.

Even though the Geary character is in the late 50's, he reminds me of the current Senator from Nevada (Reid). The prospect of Harry Reid being tied in with the mob would help explain his "accident" last year with the exercise equipment.

Geary wasn't bought, he was blackmailed into supporting Michael's Vegas expansion. Geary hates Michael.
His dramatic monologue before leaving the hearings is to be a faade to give the appearance he is helping Michael without giving the actual help Michael really needs during the hearings (which would hurt Geary politically.)

Maybe it's just the way I'm reading the scene, but it seems like he's so obviously saying "look at me - I've been bought!" with that speech, that surely all his colleagues on that panel will now suspect him / try to destroy him for being corrupt and in the pocket of a mobster. A powerful friend like that works best when no-one knows they work for you, the impact is lessened if everyone knows to beware Geary, because he's Michael's puppet.

My read on the scene is just Geary weaseling his way out of an uncomfortable position. On the one hand, as Michael's pawn he can't oppose the guy publicly. On the other, he doesn't want to tip his hand to the Senate. Geary, being a politician, finds a solution that allows him to save face to both Michael and his colleagues on the commission without having to do a damned thing.
I'm afraid that you underestimate the number of subjects in which I take an interest!