Take a look at that picture - He looks unhinged doesn't he? Kavanaugh lost the moment that Trump decided to give in to the optics and order an investigation. The Senate had effectively voted him in when Trump made his announcement.
They say there isn't enough time for the FBI to get to the bottom. Be that as it may, that is not what will get Kavanaugh. What will bring him down is his drinking reputation, one that he never apologized for but instead made a big thing of it to the point of insulting the committee, "I like a beer. don't you?" and never answering straight about the extent of his drinking habit. The FBI may not find enough information on the attempted rape but his drinking is sure to come up. Also they will find that it went past his high school years.