Here is a clip from the screenplay. It has extra content from the author that provides a little more insight into the characters thoughts. Why does Tom walk in "sheepishly"?

MICHAEL
It was very kind of you to come to
my home on this occasion, Senator.
My wife has been very concerned
with making a good impression on
the people who are our neighbors,
and your appearance here has made
her very happy. If I can ever
perform a service for you, you only
have to ask.

The door opens, and Hagen sheepishly makes his way in.

MICHAEL
My lawyer, Tom Hagen. He arranged
this all through your man Turnbull.

SENATOR GEARY
I thought we would meet alone.
...
forward to
...

SENATOR GEARY
Let's forget the bullshit, I don't
want to stay here any longer than I
have to. You can have the license
for two hundred and fifty thousand
in cash, plus a monthly fee equal
to five percent of the gross...

Michael is taken aback; he looks at Hagen.

SENATOR GEARY
...of all three Corleone hotels.

Hagen is frustrated; all his information was wrong.

MICHAEL
Senator Geary, I speak to you as a
businessman who has made a large
investment in your state. I have
made that state my home; plan to
raise my children here. The
license fee from the Gambling
Commission costs one thousand
dollars; why would I ever consider
paying more?

SENATOR GEARY
I'm going to squeeze you, Corleone,
because I don't like you; I don't
like the kind of man you are. I
despise your masquerade, and the
dishonest way you pose yourself and
your fucking family.

VIEW ON HAGEN

glances at Michael.

VIEW ON MICHAEL

makes no outward reaction.

MICHAEL
(quietly)
We're all part of the same
hypocrisy, Senator. But never
think it applies to my family.

SENATOR GEARY
All right, then let me say you'll
pay me because it's in your
interests to pay me.

VIEW ON GEARY

rising.

SENATOR GEARY
I'll expect your answer, with
payment, by tomorrow morning. Only
don't contact me...from now on,
deal only through Turnbull.

He is almost out the door.

MICHAEL
Senator...
(cold and calm)
...you can have my answer now if
you'd like.

Geary turns back.

MICHAEL
My offer is this. Nothing...not
even the thousand dollars for the
Gaming Commission, which I'd
appreciate if you would put up
personally.

Geary returns Michael's hard look; then laughs and leaves.
Slowly Michael turns to Hagen.

VIEW ON HAGEN

embarrassed at being so off the mark.

MICHAEL
It's all right, Tom, we'll talk
later. Tell Frankie Pentangeli I'd
like him to have dinner at my
family table before we do business.