Connecticut’s public colleges and universities have walked on a fiscal knife’s edge for years. Forced to frequently raise fees and tuition to offset dwindling state aid, higher education faces a new threat from the coronavirus — potentially worse than the initial surge that closed campuses last spring. Simply put, what happens if students decide it’s cheaper — or healthier — to learn remotely, even after the pandemic? Even a small shift in attitudes that saps 10% or 20% of fee receipts could push systems already in fiscal jeopardy into grave peril.