It might depend on the interpretation of "legitimate", and make more sense if "are legitimate" is interpreted as "ever legitimate". For example, could a milita

It might depend on the interpretation of "legitimate", and make more sense if "are legitimate" is interpreted as "ever legitimate". For example, could a military coup in North Korea be "legitimate"? They give some more detail in their linked earlier paper: Similarly, while 43 percent of older Americans, including those born between the world wars and their baby-boomer children, do not believe that it is legitimate in a democracy for the military to take over when the government is incompetent or failing to do its job, the figure among millennials is much lower at 19 percent. In Europe, the generation gap is somewhat less stark but equally clear, with 53 percent of older Europeans and only 36 percent of millennials strongly rejecting the notion that a government’s incompetence can justify having the army “take over.” http://www.journalofdemocracy.org/sites/default/files/Foa%26Mounk-27-3.pdf http://www.journalofdemocracy.org/sites/default/files/Foa%26... While still striking, and while I still wonder whether generational differences in terminology are a factor, the addition of "when the government is incompetent or failing to do its job" does make it more plausible.