The Obamas have released their 2007 tax returns following the release of their earlier returns. The total was a cool $4.2 million in 2007, $4 million of which is accounted for from Barack’s book sales.

Here’s the scoop from Yahoo! News:

PHILADELPHIA - Democratic Sen. Barack Obama and his wife, Michelle, made $4.2 million last year as widespread interest in the presidential candidate pushed the sales of his two books.

In tax returns the campaign released Wednesday, the Obamas reported a significant jump in their income from the previous year as profits from the books “Dreams From My Father” and “The Audacity of Hope” accounted for some $4 million. The Obamas paid federal taxes of $1.4 million and donated $240,370 to charity.

Their salaried income was $260,735, which included his $157,102 salary as a U.S. senator and hers of $103,633 as vice president of community and external affairs at the University of Chicago Medical Center.

For part of 2007, Michelle Obama collected a salary for serving on the board of Westchester, Ill.-based TreeHouse Foods Inc., which produces pickles, nondairy powdered creamer and other products. She resigned in May after two years on the board.

The position had generated some complaints because TreeHouse is a supplier to Wal-Mart, and Barack Obama has criticized some of Wal-Mart’s policies and treatment of employees.

The Obamas reported $29,443 from Treehouse Foods.

In 2006, Obama and his wife reported income of $991,296. The sum included Obama’s Senate salary of $157,082 and his wife’s earnings of $273,618 from her position as an administrator at the University of Chicago Medical Center. Michelle Obama also earned $51,200 in director’s fees from TreeHouse Inc., a food distributor.

Mental note: Write a book, then run for the presidency.