When Vice President Dick Cheney stumped at Allegheny College in 2004, school leaders welcomed the exposure of a national campaign event but disliked a condition now common among political parties: that the candidate controls who attends.

It led to a new policy at Allegheny requiring half the seating at future such gatherings to be open to the campus community.

Now, with the 2008 presidential campaign under way, the liberal arts campus with 2,100 students is going national with an effort to ensure that colleges are not used as convenient backdrops for events that resemble town meetings but are, in fact, limited to handpicked supporters.

The school plans to send letters to the leaders of 600 colleges and universities asking them to consider policies that would open up such events on their campuses.

"Colleges and universities, of all places, really are about open discussion and debate," said Allegheny President Richard Cook. "I believe that campuses are frequently chosen because they have that reputation."

Dr. Cook said the very label "town meeting" implies a free opinion exchange. "But that's not what happens at an increasing number of these events," he said.

Officials plan to hold a news conference Monday to promote formation of what they have dubbed the Soapbox Alliance, a coalition of campuses that either have an open event policy or will work toward developing one by Sept. 1, 2008. The event will coincide with the 150th birthday of Ida Tarbell, an author and crusading journalist considered by many to be Allegheny's most famous alumna.

College officials say they have begun meeting with campus leaders in Pennsylvania and, based on initial feedback, are optimistic the idea will gain support.

Dr. Cook said the intent is not to curb such events but to ensure they unfold as billed. He said the school's policy covers Democrats and Republicans alike, and the national effort is also party neutral.

"It's not a party issue, really," he said. "It's a matter of trying to promote a healthy democracy."

In September 2004, Allegheny received a request from the Bush-Cheney campaign to rent a campus gymnasium for its town hall meeting on Oct. 13. The event was "ticketed," meaning the campaign doled out passes in advance and thus controlled who would be in the building, Dr. Cook said.

Some on campus questioned if even allowing the event amounted to a political endorsement, but Dr. Cook said Allegheny proceeded believing it would be positive for the campus and the community and promote student engagement.

College officials said turning down the request might have been seen as Democratic favoritism.

Dan Shea, founder of Allegheny's Center for Political Participation, led the campus effort to enact the new rules. "Everyone realizes that campuses have to come together on this," he said.

Jerry Shuster, a political communication professor at the University of Pittsburgh, said he, too, believes schools will sign on. It will be unpopular with campaigns, but candidates tempted to move off campus would appear to be shunning debate and "will be embarrassed into" accepting the new rules, Dr. Shuster said.