They have seen this politicization on full display in recent weeks, with the campaign of former President Donald Trump criticized for the way that Trump turned the gravesites of soldiers who died in the chaotic withdrawal from Afghanistan three years ago into a campaign photo-op that apparently violated Department of Army regulations. But in recent cycles, as candidates have increasingly lacked direct military experience, campaigns have used the endorsements of prominent retired military to try to signal a candidate’s fitness as commander in chief.