US default on the debt would be unconstitutional. Clearly and explicitly. If other laws make it impossible to pay our debt, at least one of those other laws is invalid in that application. Maybe that's the debt ceiling. Maybe that's something stopping us from monetizing some portion of the debt. Maybe something else, though not arbitrarily seizing property because that's otherwise protected by the Constitution.

I'm not claiming any of these are good options, but "the debt ceiling will make us default" seems incorrect and irresponsible.