Misquoted.
Specifically, in the first sentence, the word written by Twain in his notebook (spanning 1904-1908) was “republican”, not “democratic”. More importantly, the excerpt was the fifth paragraph in a longer note by Twain, and it was preceded by four paragraphs which provide meaningful context for his use of the word “patriotism”. Here are the five paragraphs:

“A Patriot is merely a rebel at the start.

In the beginning of a change the patriot is a scarce man, and brave, and hated and scorned. When his cause succeeds, the timid join him, for then it costs nothing to be a patriot. The soul and substance of what customarily ranks as patriotism is moral cowardice and always has been.

In any civic crisis of a great and dangerous sort the common herd is not privately anxious about the rights and wrongs of the matter, it is only anxious to be on the winning side.

In the North, before the war, the man who opposed slavery was despised and ostracized, and insulted. By the "patriots." Then, by and by, the "patriots" went over to his side, and thenceforth his attitude became patriotism.

There are two kinds of patriotism -- monarchical patriotism and republican patriotism. In the one case the government and the king may rightfully furnish you their notions of patriotism; in the other, neither the government nor the entire nation is privileged to dictate to any individual what the form of his patriotism shall be. The gospel of the monarchical patriotism is: "The King can do no wrong." We have adopted it with all its servility, with an unimportant change in the wording: "Our country, right or wrong!" We have thrown away the most valuable asset we had:-- the individual's right to oppose both flag and country when he (just he, by himself) believed them to be in the wrong. We have thrown it away; and with it all that was really respectable about that grotesque and laughable word, Patriotism.”