Utah representative Ben McAdams, a Democrat, warned ominously this week that a “day of reckoning is coming”. It’s the kind of sober language typically used to describe a climate crisis which – if we continue on with business as usual – could end human civilization as we know it. McAdams, though, was describing a decidedly less grave threat, if it can be considered a threat at all: the federal deficit. He and 26 other members of the so-called Blue Dog Coalition – centrist and fiscally-conservative Democrats – are pushing for a constitutional amendment that would prohibit the federal government from...