What it is:
A bag man is a person who solicits contributions to political parties or political causes on behalf of someone else.
How it works/Example:
Let's say that Company XYZ wants to fight the passage of a new law that would regulate its industry. It wants to raise contributions for a political action committee (PAC) that would serve this purpose.
Company XYZ could hire a bag man to meet with donors and collect contributions from Company XYZ's vendors, suppliers and employees. The bag man gathers the contributions for Company XYZ, keeping some percentage for himself as a fee. Company XYZ then turns around and donates the money to the PAC.
Why it matters:
The activities performed by a bag man are generally considered legal, at least as far as above-the-board political contributions are concerned.
However, sometimes the term "bag man" refers to a person in charge of collecting the payoffs from racketeering, bribery and corruption. For example, the Mafia used bag men to collect the payoffs owed to the crime bosses. Obviously, the context in which the bag man operates is the key determinant when deciding whether the bag man's activities are legal or illegal.