Forget about political suicide (which it would be), I think that there would be a violent revolt against a March/April 2020 style "lockdown" in the US.
I'm not sure about that, mostly because I doubt anyone would listen. It would be like announcing that everyone should clap once and turn in a circle before leaving the house. Nobody would do it, and they would be less likely to listen to anything else too.
Nobody is going to announce a lockdown of any type anyway. It's a blunt tool to buy time. We don't need to buy time for anything anymore, we need to use the time we've already got. At least in the US.
For every mandate that's been set or not set for most of the pandemic stuff (mostly masks, but some other distance or closing) how much enforcement of them was actually going on? I mean, people did them but that's because they followed along not because of some enforcement. Certainly not large amounts of enforcement required.
Was anyone (or more than a few) actually fined or jailed or whatever by the government for not wearing a mask? Lots of dirty looks or asked to leave businesses, but that's not really enforcement. Unless someone pressed the issue with a business and became unruly. But, the enforcement came after the unruly behavior.
For instance, all the airplane stories we've seen. They always seem to be about a fight not just someone sitting there. They always seem to play out as person not wearing a mask, flight crew requests they mask, they refuse, flight crew requests again and adds some leverage like they will not leave the gate or will deplane them, person starts a fight, police deal with them for fighting. If someone just sat quietly in their seat after takeoff and removed their mask then using supreme self control ignored everything in a zen state. They might still be asked to leave, but it would certainly be a harder call by the flight crew. I'm certainly not advocating that, and I don't think anyone could be that zen. The flight crew would clearly keep asking them, and anyone unwilling to just wear it isn't likely to be the zen type.