U.S. Democratic presidential candidate Barack Obama, who has vowed to run a dignified campaign, has attacked his rival Hillary Clinton for her “personal, financial and political ties to India” in a memo leaked to the New York Times by the Clinton camp.

The caustic memo referred to Hillary Clinton as D-Punjab, a reference to Hillary’s joke at a fund raiser at an Indian American’s home in Maryland that “I can certainly run for the Senate seat in Punjab and win easily.”

Seemingly prompted by envy of Hillary’s close ties to the Indian-American community and her success in raising funds from this rich community, the memo attacks Bill Clinton’s stock ownership in an Indian company, outsourcing to India and the Clintons’ close ties to New York hotelier Sant Chatwal.

The Obama campaign memo reads:

The Clintons have reaped significant financial rewards from their relationship with the Indian community, both in their personal finances and Hillary’s campaign fundraising. Hillary Clinton, who is the co-chair of the Senate India Caucus, has drawn criticism from anti-offshoring groups for her vocal support of Indian business and unwillingness to protect American jobs. Bill Clinton has invested tens of thousands of dollars in an Indian bill payment company, while Hillary Clinton has taken tens of thousands from companies that outsource jobs to India. Workers who have been laid off in upstate New York might not think that her recent joke that she could be elected to the Senate seat in Punjab is that funny.

The Asian-Indian community, one of the richest in the U.S. is of course not amused by the Obama campaign’s attack. U.S.-India Political Action Committee chief Sanjay Puri told the New York Post:

For any candidate to imply there is something wrong with getting Indian-American support, that is upsetting – very upsetting – for our members.

Indian Americans for Hillary 2008 have already raised $1 million for Hillary and plan to raise a total of at least $5 million for her.

In a damage control exercise, Obama claimed the nasty attack as “a screw-up on the part of our research team” and that neither he nor his senior staff had seen the document.

After the storm of negative publicity that followed, Obama told the The Des Moines Register’s editorial board:

I thought it was stupid and caustic and not only didn’t reflect my view of the complicated issue of outsourcing … it also didn’t reflect the fact that I have longstanding support and friendships within the Indian-American community.