This is exactly what happens at the Swiss Federal Institute of Technology (ETH) Zurich. By law, ETH is required to admit any Swiss secondary school graduate - to compensate, the courses are designed to filter out students. As a result, about 50% [1] of the entering class will drop out. This system is not likely to be popular in the US.
[1] http://tech.mit.edu/V126/N41/41Switz.html