The nature of that action could have seriously affected Mike's plan. Who knows. He could have said, "I'll show you. Take your money and shove it. I'm bringing in the FBI."
I highly doubt it. I'm sure that Geary was a senator that already had plenty of skeletons in his closet way before dealing or attemting to deal with Michael.
His shady background is probably one of the reasons that Michael attempted to do business with him.
And Geary went into that meeting with Michael a seasoned pro in how he laid out his demands. The way that he did so showed that he had done it before. Only mistake is that he underestimated Michael and how far his reach went.
