Curiously enough, not a single professor from the Wharton School, one of the most prestigious business schools of the US, which is part of the University of Pennsylvania, was a signatory to this letter.
Modi was invited by the Forum to deliver the keynote address at its annual conference on March 23 via video conference but it was cancelled less than 50 hours after three Indian-American professors from the University of Pennsylvania organised and sent a petition signed by about 135 people.
The number of petitioners had jumped to more than 250 by last night, according to one of the authors of the petition campaign.
"It is the result of the pressure that we were able to bring over the organisers (Wharton India Economic Forum) in the last two days. I am very very proud of Wharton as well as the Penn University. But it still concerns us that he was invited in the first place," Toorjo Ghosh, assistant professor at the University of Pennsylvania, one of the three professors, said.
Ania Loomba, the Catherine Bryson Professor of English and Suvir Kaul, the AM Rosenthal professor of english were the other two professors to have instantly organised the campaign after exchange of some emails Friday night.
"There was not one Wharton Professor who signed onto this letter. They were not involved till we brought on the pressure. The pressure was brought by a bunch of faculty members at the Penn, and also some community members, some attorneys," Ghosh said, acknowledging that this was quite strange.
"I think it is strange. This could have been for a number of reasons," he said.
Organisers of the annual Wharton India Economic Forum (WIEF) confirmed that it was the petition that was basically instrumental in reversing their decision on Modi.
"Only one petition to our knowledge," Tanmay Mishra, on behalf of the WIEF said.
"Mr Modi's office was informed before the press statement," he said in response to another question.
"Our team felt that the potential polarising reactions from sub-segments of the alumni base, student body, and our supporters, might put Mr Modi in a compromising position, which we would like to avoid at all costs, especially in the spirit of our conference's purpose," the WIEF organising committee said yesterday in a statement.
Asserting that it stands by its decision to invite Modi, the organising committee said it believes that this course of action would be the most appropriate in light of the reactions of the multiple stakeholders involved.
"Therefore, we as a team, would like to apologise for being a catalyst that may have put Mr Modi and the Wharton School administration in an difficult position," the statement said.
Arguing that they do not endorse any political views and do not support any specific ideology, the statement said their goal as a team is only to stimulate valuable dialogue on India's growth story, and to act as a forum where students and audiences interact with influential leaders from across India.
The student organising body was extremely impressed with Mr Modi's credentials, governance ideologies, and leadership, which was the primary reason for his invitation, the statement said.
"However, as a responsible student body within the University of Pennsylvania, we must consider the impact on multiple stakeholders in our ecosystem," the organising committee explained.
"Mr Modi's keynote address at Wharton India Economic Forum has been cancelled," the Wharton India Economic Forum said in a statement, which was welcomed by the organisers of the petition campaign.
"I think one of the things that concerns us and continues to be is an attempt by a number of folks from his (Modi's) camp as well as some camps in the business community trying to differentiate and distinguish between his economic policies versus his human rights records," Ghosh said.
"We believe that the two are absolutely connected and that is the reason why Gujarat has developed in a way it has," he said.
Ghosh, who besides his teaching, works among the poor and slums in India.
Having got what he wanted, Ghosh said he and his team would continue to "expose" Modi.
"I think it is important to keep talking about what development is. The model that Narendra Modi has put forward is seriously flawed and is based on some extremely egregious flouting of human rights. That is his economic model," Ghosh said.
"Gujarat has some of the worst human development index report. We need to unpack this rhetoric what development is. We will continue to do that," he added.
The anti-Modi petition said that it was incomprehensible to the signatories that this was the man who the Wharton India Economic Forum wished to celebrate as an exemplar of economic and social development.
"We find it astonishing that any academic and student body at the University of Pennsylvania can endorse ideas about economic development that are based on the systematic oppression of minority populations, whether in India or elsewhere," the petition said.
"Mr Modi still does not have a US visa to enter the US, but Wharton plans to present him on Skype to the audience. Recently there have been efforts to whitewash Modi's grim record and to grant him international respectability. Wharton's invitation lends itself to doing just that," the signatories of the petition argued.
"We urge the Wharton India Economic Forum to revoke their invitation to Narendra Modi. If it does not do not do so, we pledge to protest against his presence – virtual, as it will be – given that he remains ineligible for a US visa, in a variety of ways, including at the meeting of the Forum," the signatories said in the petition.
"We will also do all that we can to continue to educate our community about the incalculable and continuing harm done by Modi's brand of politics to the secular values enshrined in India's constitution," they said.