Hari Sreenivasan:

Congress is back at work in Washington starting tomorrow. And last week we saw former Vice President Joe Biden add his name to the very long list of candidates for the Democratic presidential nomination.

So we asked Special Correspondent Jeff Greenfield to join us for some political analysis and perspective. Good to have you at the table.

First, let's talk a little bit about the Biden factor. This is something that has been almost a foregone conclusion, it's been such a long windup. Here he is but really he spends the first few days of his official part of the campaign dealing with his past and his legacy and the Anita Hill hearings.