Actually I think the above statement is correct. If the U.S. was a pure democracy, the will of the people would be ultimate. As a constitutional republic, the constitution is ultimate, and in the U.S.'s particular implementation of the republic, the will of the people would mandate a law, and the supreme court would determine if that law comports with the constitution or not.
And then the people vote to change the constitution, as they are doing in California on next Tuesday.
Majority rules with minority rights. The judges are there in part to ensure the rights of the minority are respected.