The rhythm of "Clementine" is nothing like any waltz and very close to 3/4 marches like "Lochanside" or "When the Battle's O'er". The dotted-pair downbeat is what gives it the military feel.

(All the ABC for "Clementine" I can find on the web puts the downbeat on what I would think of as beat 2 - is it always notated that way?)