Corker is against the stimulus package. This was a procedural vote repeated over and over again before some of you go off the deepend and bombard his office.
His agreement to limit debate facilitates the bill advancing. When fewer than 60 Senators agree to limit debate, the matter usually dies on the spot. It certainly stalls at that point, until 60 senators agree to limit debate. The only reason his vote "doesn't count" is that there weren't exactly 60 in favor of limiting debate. He's giving cover to his sisters from Maine and his brother from Pennsylvania.
Bombarding his office is not inappropriate, if one feels this bill ought to die an ignoble death right here in the Senate.