At my alma mater, there were established locations in the dining hall and the library lobby with tables from which you were allowed to spread your political/religious/etc message. But you had to do it from behind the table, you had to book a table in advance on a first come/first served basis, and everyone had equal access (except those with hate messages).

(Edit: Aggressive Christians weren't tolerated at my school, whose cherished unofficial motto was "Communism, atheism, free love.")