Alcoholism is a disease. People will debate whether it is a disease of the mind, of genetics, or of circumstances. I don't have the answer to that debate, and frankly I don't care because when you try to pinpoint 'why,' it can often lead to blaming another person, an incident in your past, or circumstances.
You now have six-year campaigns for the Senate - you never stop running. It's not uncommon for a member of the Senate to have a fundraising breakfast, a fundraising lunch and a fundraising dinner, and then when the Senate breaks for the week to go home, more fundraisers. And that's driven by the cost of campaigning.