ALBANY – A group of Republican students at Rensselaer Polytechnic Institute has said the school’s president, Shirley Ann Jackson, defied the will of undergraduates in approving Senator Clinton as the speaker at Saturday’s commencement.

The group, RPI College Republicans, said in a series of faxes to area reporters this week that Ms. Jackson and the school’s board of trustees ignored a list of potential speakers voted on by students at the prominent engineering school in Troy. That list did not include Mrs. Clinton.

The Republicans threatened to “respond in kind” if Ms. Jackson did not replace Mrs. Clinton as a speaker, and they planned a series of events leading up to commencement dubbed “12 Days of Hillary.” The group said Ms. Jackson denied their requests to provide more information on the selection process.

A spokeswoman for Ms. Jackson, Theresa Bourgeois, said the charges were false. She said that Mrs. Clinton’s name was indeed on the list provided to Ms. Jackson by students and that the trustees followed the “traditional process for selecting a commencement speaker.”

A spokesman for the College Republicans, Kenneth Girardin, did not respond to messages seeking comment.

In its most recent press release, the RPI Campus Republicans said they obtained a list of the 10 most popular picks among students for commencement speaker. A talk-show host and comedian, Conan O’Brien, topped the list, which also included, among others, the software developers Steve Jobs and Bill Gates, and the former secretary of state, Colin Powell.

The Campus Republicans maintained that Mrs. Clinton’s selection as the commencement speaker is related to Ms. Jackson’s political support for the former first lady. Ms. Jackson was appointed to head the Nuclear Regulatory Commission by Mrs. Clinton’s husband, President Clinton, in 1995 and has contributed to the former first lady’s political campaigns.

“Senator Clinton, who was not on the list presented to Dr. Jackson, was somehow selected to speak at RPI’s commencement this Saturday, May 21,” the release said. “The RPI administration has, to date, failed to disclose whether any of the speakers on the list were invited prior to Senator Clinton being approached.”

One of the four officers on the school’s board of trustees, Paula Simon, said yesterday she has “no recollection” as to whether Mrs. Clinton’s name was on the list of candidates presented to the board by students. Ms. Simon, an executive with the Bronx-based Wildlife Conservation Society, defended Mrs. Clinton as a speaker.

“She’s an influential public figure and she deserves the kind of attention she will get,” Ms. Simon said. “And she will bring positive press to RPI overall.”

Ms. Jackson, the first black woman to earn a Ph.D. from the Massachusetts Institute of Technology, has led RPI since 1998, raising the school’s profile – and hundreds of millions of dollars for its endowment. She also is among the best-compensated school presidents in America, and she is highly sought after as a member of corporate boards of directors.

According to the Chronicle of Higher Education, Ms. Jackson received compensation of $891,400 from RPI in 2002, making her the highest-paid college president in the nation that year. She earned an additional $591,000 for work as a board member at eight corporations. She was named last year to the board of directors of the New York Stock Exchange.

Rensselaer Polytechnic Institute has 32 active trustees, of whom four are officers. In addition to Ms. Jackson, they include Ms. Simon; a Baltimore businessman, Samuel Heffner; and a federal judge in Washington, D.C., Arthur Gajarsa.

Ms. Jackson, who has a soft-spoken manner, a keen intellect, and an appetite for deep reflection, is a frequent speaker at colleges and civic events. She recently cut the ribbon on an $82 million biotechnology center in Troy that benefited from public money secured by the majority leader of the state Senate, Joseph Bruno, a Republican of Rensselaer, and under her leadership the school is building a cutting edge experimental media and performing arts center.

According to records maintained by the Federal Election Commission, Ms. Jackson donated $1,000 to the Hillary Rodham Clinton for U.S. Senate Committee in 2000; and $500 to the Friends of Hillary campaign committee last August. She also donated $500 to Al Gore’s presidential campaign in 2000.