That's a bit nebulous. I'd say everything comes down to asking what it is you wish to accomplish. Then stepping back and asking if X is accomplished by solution Y. You and I won't always agree on what it is we wish to accomplish, thus the question is a political one first.
It's not the silver that makes it legal tender. It's the fact that it's declared legal tender. Furthermore, there isn't enough US money in existence for everyone to pay their taxes, which was the point.