As cap-and-gown season gets underway at American colleges and universities, graduates and their loved ones will be getting an earful from left-wing commencement speakers, according to a report.

Liberal speakers will outnumber conservatives by at least 6-to-1 at the nation's top 100 schools as ranked by U.S. News & World Report, according to conservative watchdog group Young America’s Foundation. Among the top 10 of the list--which includes schools such as Princeton, the University of Chicago and Duke--none is hosting conservative speakers.

“Our 2015 survey shows the conservative blackout on college campuses has only gotten worse,” Ron Robinson, president of Young America's Foundation, said in a statement to FoxNews.com. “While conservatives won the national elections by a wide margin, campuses have doubled down on liberal speakers--with zero elected conservative officials scheduled to speak at our nation's top schools.”

“Our 2015 survey shows the conservative blackout on college campuses has only gotten worse.”

- Ron Robinson, president of Young America's Foundation

Robinson said the data shows schools and the general public are going in different directions.

“The country is more conservative and campuses have a larger selection of conservative leaders to invite, yet higher education continues to offer only a one-sided education,” he added. “This trend will be detrimental to the development of our country’s future leaders. Students are not getting the full picture about government policy or learning about the Constitution, American exceptionalism, or free market economics.”

Every year, YAF takes the list of the top 100 hundred universities, determines which speakers are scheduled at each school and then attempts to determine each one's political orientation using the following criteria:

  • Public financial contributions to political candidate or causes
  • Public statements revealing ideology
  • Public statements in support of 2012 presidential candidates
  • History of running for office or holding political appointments
  • Self-identified as partisan

The YAF found nine Obama administration appointees will deliver 2015 addresses, compared to 14 George W. Bush administration officials during the two terms of his presidency. Coincidentally, Bush was the only conservative politician scheduled to speak. He will be giving a commencement speech May 16 at Southern Methodist University in his home state of Texas.

Some of the current liberal officials speaking this spring include Vice President Joe Biden at Yale, Virginia Gov. Terry McAuliffe at the University of Virginia, Sen. Michael Bennet, D-Colo., at the University of Denver, Rep. John Lewis, D-Ga., at Georgetown University, and Los Angeles Mayor Eric Garcetti, who will address graduates at Columbia University.

Lehigh University, in Bethlehem, Pa., does not factor in political ideology in extending invitations to speak, said a spokesman.

“Lehigh University prides itself on the variety of our commencement speakers and the way we choose them through an open, public page that staff, faculty, students and alumni are welcome to visit and provide their nominations and feedback” Lehigh spokesman Jordan Reese told FoxNews.com.

Reese points out that the school never has asked speakers about their political affiliation and has had several conservative speakers in years past, including Republican governors of New Jersey Thomas Kean and Christine Todd Whitman, as well as Steve Forbes and former Vice President Dan Quayle.

This year, Walter Issacson, CEO of the Aspen Institute—whom the YAF has identified as liberal in the study—will be speaking at Lehigh.

“I couldn’t be more delighted to be able to have Walter Isaacson deliver this year’s commencement address,” Lehigh Interim President Kevin Clayton said in a recent press release about the ceremony. “With his unique perspectives on some of history’s most accomplished and fascinating figures, I’m sure he will have interesting insights to share with our graduating students and their families.”

Perry Chiaramonte is a reporter for FoxNews.com. Follow him on Twitter at @perrych