The check elected officials have on this is to pack the courts. This is what FDR threatened to do to get through (at the time unconstitutional, now magically "not") a bunch of popular legislation.

FDR is written about phenomenally in US history books for reasons that don't seem to match the reality of what happened. We can separate foreign policy wins from domestic policy losses, just like we do now.

The now-heralded New Deal was getting torn apart by the Supreme Court, program after program for half the decade. And the remaining parts of the New Deal still exist on shaky constitutional ground if you really look at how much of an abberation they are and how they survived. Spoiler alert, for things that remain its nearly impossible to get standing in Federal Courts to question them and the people that could get standing aren't interested and benefit from them.

FDR threatened to pack the courts, just like modern presidents and party constituents demand.

It was actually very partial that the FDR-era Supreme Court backed off from that threat. So to consider our current Supreme Court to be the aberration is inaccurate, it is even more autonomous.

Everything I look at gives me the opposite conclusion of the public discourse, except when I'm in very small legal circles.

Isolating yourself to small legal circles can unfortunately open yourself to the vulnerability of mistakenly appealing to the authority of legal training that has specifically been tailored for success in the system we're in, which may optimize for coming to conclusions that help you win cases rather than optimizing for some other analysis. Looking at the bigger picture is an entirely different skill set than having legal training to be a good lawyer, so I think it's folly to place in special stake in "small legal circles" for this and in the worst case, might usher you into an echo chamber built out of practical adaptation.

If I wanted a healthy view I might include those with legal backgrounds but they would only be a small selection of the landscape of ideas to draw from, I certainly wouldn't place special stock in the "legal" community.

I'll watch out for that. But ultimately I do want my view of the world to be the law of the land, which means "win cases", specifically reflecting my view and my currently obscure arguments. My observation is that populist arguments are the ones that fail because they don't understand the mechanisms and obscurity.

A now-less-obscure view is based on the observation that the New Deal used a completely novel and expansive view of the interstate commerce clause that completely subjugated the states and essentially created a parallel nation overlaying the collection of states - what was called the Federal government for practicing federalism was now only nominally federal, as Congress now only grants exceptions for state autonomy just to retain support on occasion. Despite how disruptive it would be to review this arrangement, this 100 year use of the interstate commerce clause is completely on shaky constitutional ground

The entire federal agency apparatus could be Thanos-snapped out of existence, just like the 1930s Supreme Court was doing

(I don't want that specific thing to happen, and I don't see the alternate federal authority for most of the agencies and their regulations if it were to happen, so that would be very disruptive)

I don't view the New Deal changes in constitutionality as prevailing through some from of reasoning of arguments per se, just projection of power. Projection of power is unlikely to be changed through lawfare. Usually it is not relinquished without violence. The violence that set the stage for consolidation of federal power, IMO, was in large part the civil war (removal of secession as a check on federal power, IMO the most powerful check states had) but of course also the concerns from the aftermath of WWI.

The fact the ICC was used is the least consequential part of the whole thing. That's just what was picked by the whig-gods to present legitimacy to the projection of power. Could have just as well been a proclamation from god under some other system. If the ICC expansion non-sense is struck out of some kind of convenience for some matter they are attending to, I don't think it changes much, just means the priest will utter some other magic phrase.

Only if it could be done in an apolitical way, which seems impossible in the current political climate. The legitimacy of the US Federal Government depends on the perceived continuity of the (now mythical) constitutional order. If one party or the other packs the court without bipartisan support for their nominees in the Senate, it would be denounced by the other as an authoritarian end-run around the constitution--as a revolutionary rather than a mere procedural act. IMO this would be more likely to foment disunion than it would be to restore the bygone constitutional order.

The fabrication of legitimacy is indeed the main task of the supreme court.

However violence is another way to project legitimacy. Putting someone away for life or drone striking a goat farmer provides real legitimate proof of power.

The government is much stronger than it was 100 or 200 years ago. So perhaps it can dispense with appearances of judicial legitimacy using the currency of violence. It's not clear they need to continue with the fiction of an impartial court to hold their grasp; like a space ship they can jettison that hallowed out rocket having already safely been placed into orbit.

The size of the Supreme court is not defined in the Constitution. So, packing the court is not unconstitutional. It is dishonest and shady as hell. But, the only check on the power of each branch are the other two branches that don't desire to be sidelined by one branch growing more powerful. All three branches are supposed to be in contention for power within the bounds of their interpretation of the Constitution. It is the duty of the other two branches to deem an action of the third branch as unconstitutional.

But, the system has been broken over time. Congress abdicated the majority of their power to the executive and somehow judicial became the official arbiters of constitutionality.