Authority does carry some weight, depending (pun intended) on what qualifies the authority. When appeal to authority IS the final argument it is by convention such as the U.S. Supreme Court. And I guess if you extended the argument far enough you might just come to appeal to populace (in a democracy) as elected judges can be put out of office and appointed judges can be impeached and their appointers put out of office. But then again, the majority can be wrong! Are we getting close to post hoc, ergo proctor hoc yet?