Should post-secondary education be free?

Last winter, the most important student unions in Quebec went on strike against proposed tuition fee increases. Even though fees in Quebec are extremely low by North American standards (just over $2000/year) the strikes sparked a massive social movement for affordable education in particular and against austerity in general.

Half a year later, the government of Quebec has been defeated in a recent election, and the incoming party has announced that they plan to freeze tuition fees. A huge victory for the students, but not enough for one group. CLASSE, which represents more than 100,000 students, now demands completely free post-secondary education. After all, if elementary and secondary education are both available to all regardless of ability to pay, why not a university degree?

What do you think? Should education be as free as air and water?