Liberals are idiots.
The Constitution is NOT hard to understand. Where does it give the government the power to force the citizens to do something like that??
I would wager that a poll of liberals would find that the vast majority would believe that a mandate to buy broccoli would be perfectly Constitutional. They seem to believe that when something is good for people, then it must be Constitutional and if something is bad for people, then it must be unConstitutional.
The actual words or thoughts of the Founders don't enter into the judgement. Liberals simply decide what they think is reasonable and then insist that our Founders would have also found the same thing reasonable.
Liberals believe that gun-control laws are reasonable. They believe that our Founders would have believed that gun-control laws are reasonable.
Liberals entirely overlook the history of colonists in occupied Boston being forcibly deprived of their arms by the army (the Redcoats) of their own government.