Aug. 8 (Bloomberg) -- Goldman Sachs Group Inc. Chairman Lloyd Blankfein endorsed Democratic New York Senator Hillary Clinton's presidential bid, a day after her opponents sought to portray her business support as more of a burden than a blessing.

Blankfein's backing follows an endorsement in April from Morgan Stanley CEO John Mack, who was one of President George W. Bush's biggest fund-raisers. Clinton has increased her donations from Wall Street constituents during her time in the Senate, and took in at least $424,545 from the top 10 investment banks in the second quarter for her presidential campaign.

Democratic rivals Barack Obama and John Edwards are trying to portray Clinton as an ally of big business as they court the more liberal voters who cast ballots in primaries. That strategy might backfire, said Julian Zelizer, a history and public affairs professor at Princeton University in New Jersey.

``Many Democrats, left and center, are seeking the candidate with the most solid credentials and who has the best chance of defeating the Republican candidate,'' Zelizer said. ``Support from Wall Street will add to this perception and builds the case that she can attract moderate voters in the general election.''

As first lady during her husband Bill's administration, Clinton became the bogeyman of the business world after developing a plan for universal health care that companies and trade groups derided as costly and unworkable. Since entering the Senate in 2001, she has worked to win over old foes and corporate allies across the spectrum.

`Outstanding Work'

``As a New Yorker, I have seen firsthand the outstanding work Hillary Clinton has done as a senator, proving herself to be a strong and experienced leader,'' Blankfein said in a statement released by the Clinton campaign today. Blankfein, 52, was unavailable for further comment.

Yesterday, Clinton, 59, came under fire during a Democratic forum in Chicago sponsored by the AFL-CIO. Edwards and Obama have criticized her ties to corporate lobbyists, and Edwards mocked Clinton's appearance on Fortune magazine's July 9 cover with the headline ``Business Loves Hillary!''

``You will never see a picture of me on the front of Fortune magazine saying, `I am the candidate that big, corporate America is betting on,''' Edwards said.

A spokesman for Goldman Sachs, the world's largest securities firm, declined to comment on Blankfein's endorsement.

To contact the reporter on this story: Kristin Jensen in Washington at kjensen@bloomberg.net.

Last Updated: August 8, 2007 14:18 EDT