Jack Abramoff, the notorious former lobbyist at the center of Washington's biggest corruption scandal in decades, spent more than three years in prison for his crimes. Now a free man, he reveals how he was able to influence politicians and their staffers through generous gifts and job offers. He tells Lesley Stahl the reforms instituted in the wake of his scandal have had little effect.

The following is a script of "The Lobbyist's Playbook" which aired on Nov. 6, 2011. Lesley Stahl is the correspondent. Ira Rosen, producer.

Jack Abramoff may be the most notorious and crooked lobbyist of our time. He was at the center of a massive scandal of brazen corruption and influence peddling.

As a Republican lobbyist starting in the mid 1990s, he became a master at showering gifts on lawmakers in return for their votes on legislation and tax breaks favorable to his clients. He was so good at it, he took home $20 million a year.

It all came crashing down five years ago, when Jack Abramoff pled guilty to corrupting public officials, tax evasion and fraud, and served three and a half years in prison.

Today he's a symbol of how money corrupts Washington. In our interview tonight, he opens up his playbook for the first time.

And explains exactly how he used his clients' money to buy powerful friends and influence legislation.

Jack Abramoff: I was so far into it that I couldn't figure out where right and wrong was. I believed that I was among the top moral people in the business. I was totally blinded by what was going on.

Jack Abramoff was a whiz at influencing legislation and one way he did that was to get his clients, like some Indian tribes, to make substantial campaign contributions to select members of Congress.

Abramoff: As I look back it was effective. It certainly helped the people I was trying to help, both the clients and the Republicans at that time.

Lesley Stahl: But even that, you're now saying, was corrupt?

Abramoff: Yes.

Stahl: Can you quantify how much it costs to corrupt a congressman?

Abramoff: I was actually thinking of writing a book - "The Idiot's Guide to Buying a Congressman" - as a way to put this all down. First, I think most congressmen don't feel they're being bought. Most congressmen, I think, can in their own mind justify the system.

Stahl: Rationalize.

Abramoff: --rationalize it and by the way we wanted as lobbyists for them to feel that way.

Abramoff would provide freebies and gifts - looking for favors for his clients in return. He'd lavish certain congressmen and senators with access to private jets and junkets to the world's great golf destinations like St. Andrews in Scotland. Free meals at his own upscale Washington restaurant and access to the best tickets to all the area's sporting events; including two skyboxes at Washington Redskins games.

Abramoff: I spent over a million dollars a year on tickets to sporting events and concerts and what not at all the venues.

Stahl: A million dollars?

Abramoff: Ya. Ya.

Stahl: For the best seats?

Abramoff: The best seats. I had two people on my staff whose virtual full-time job was booking tickets. We were Ticketmaster for these guys.

Stahl: And the congressman or senator could take his favorite people from his district to the game--

Abramoff: The congressman or senator uh, could take two dozen of his favorite people from their district.

Stahl: Was all that legal?