You, as a patriotic American citizen, could be charged with assault and battery for trying to save the flag.
That hardly seems like a decision that lessened the power of government.
That hasn't been how it has worked out in practice. "Fighting words" have some credibility in a defense against aggression, and americans do like their flags.
If it was illegal to burn the flag, stopping it would be a law enforcement function, and the law doesn't like citizens interfering in their tasks.
So perversely I think we can make a better stand in defense of what our country and flag stand for given the current law, rather than having the flag-burning banned.