A protest planned for this evening by a coalition of Stanford student organizations is expected to draw over 500 people in response to a speech by controversial author and blogger Robert Spencer, according to the group’s Facebook event page.

The protest, a rally to be held on the lawn in front of the univiersity’s Mitchell Earth Sciences building  is the latest in a series of student protests against conservative speakers invited to college campuses after students at UC Berkeley barred self-described provocateur Milo Yiannopoulos from speaking at an event in January of this year.

Spencer, who was invited to speak by Stanford College Republicans, is well known for his vehement anti-Islamic rhetoric. Spencer is the co-founder of Stop Islamization of America, which the Southern Poverty Law Center has defined as a hate group, has written multiple books criticizing Islam, and runs Jihad Watch, a blog expressing anti-Islam views. In an open letter responding to the criticism of his invitation to speak, Spencer connected the protesters to a larger question of free speech.

“The attempt to silence through slander a divergent viewpoint should have no place in a university like Stanford,” he wrote. “A university should be a place where ideas, however unpopular, are considered on the basis of reason and evidence, and accepted or dismissed only on that basis.”

In an open letter featured in the Stanford Daily, the student organizers of the protest responded to these claims:

“We support Stanford students’ rights to free speech, but not at the expense of Stanford’s commitment to academic integrity and respect for its students,” they wrote. “Bringing a speaker who has proclaimed himself an expert despite having no training discredits not only the organizers but the school as a whole.”