I've tried to say this myself on many occasions, but this was so well put that I had to share it (I just wish I'd read it long ago). It also carries a special weight, because it was said by a war hero and former President:
To announce that there must be no criticism of the President or that we are to stand by the President, right or wrong, is not only unpatriotic & servile, but is morally treasonable to the American public. --Theodore Roosevelt, 1918
Without even trying, I've tripped over quotes showing how greatly at odds the current Administration is with this and other Presidents held in great esteem as the better Presidents in our history.
If I really made an effort to look for more quotes, I'm sure there are a ton of them from the smart and wise men we've had serving in the highest office in the land. What a sad state of affairs we're in today.