You are offered the position of Absolute Dictator of the United States for a period of 10 years. You can implement any changes to the Constitution, fire anyone, disband anything, change any law, even have people arrested and imprisoned or executed. True absolute dictatorial powers to remake the nation in the image you desire over the course of a decade.
But the catch is that you personally will be put to death at the end of the decade no matter what. It's the one thing you cannot change, cannot avoid, cannot alter in any way. Even if you do the best job ever, you will be put to death at the end of your term. So no clever 'I would change the rules so I don't' or 'I would flee to another country right before it's over' or other dodges like that. You absolutely will die after the term is over. You in essence will be performing a soldier's sacrifice, but only much more effective and individually focused. Instead of giving your life for your country in the hopes of saving it in the abstract, you personally will be able to actually save it in whatever form you think that takes, but you will absolutely be giving your life for it.
Do you take the deal?
In a way, I'm glad you added the guaranteed death caveat, because otherwise it seems too much of a perfect fantasy. But as other users have pointed out, it's not so much what you do, but what follows.
What you would need to do to have the maximum desired effect would be to act as a societal weedkiller, that is to say not just kill the plants, but the roots and seeds. You would need to make it so that even after you're gone, society does not start to regress in your absence.
This would necessitate redefining what "communism" is, and any aspect of it is immediately forbidden from being taught in school, college, or shown on TV. This would naturally include trooning out children among other nasty ideas. All communist politicians are jailed indefinitely. And we would make communism seem incredibly undesirable by conflating it with child abuse. That it is a core tenet of communist belief.
Ditto with environmentalism. Naturally I'd switch the US grid to as much nuclear power as I could realistically commission, but forests would now be managed on a bi-yearly basis and any treehugger who tries to interfere with that is deemed an enemy of the state and appropriately dealt with.
Anyone who graffitis or vandalizes public property is also a communist.
Being a dictator, I'd then do what all dictators do and elevate all of my close friends to high-ranking positions in the government, priming them to replace me. This guarantees the laws I set will remain in place for at least another 30 - 40 years after I'm gone.
Voting is changed to homesteads only, with the patriarch (father/husband) ultimately getting the final say. If you do not represent a household, you do not get a vote.
Crime is redefined in a manner that's similar to how it was in the film Demolition Man, but without the cops becoming complete pussies. Killing someone with intent, pre-meditated or not, is an automatic death sentence. And with how bad the prison state is, I'd create a division of the police whose job is solely to take these people to deserted corners and execute them. Leave them in the communities they inhabit as a reminder of what can happen to them.
The internet becomes property of the US government, and every country that wants to use it must agree they will follow US law. That includes minimal censorship and no draconian bullshit they're trying to implement.
California gets broken up into two states. No one state should have that much land and that many people.
Texas gets broken up into two states, East and West. No one state should have that much land and that many people.
X becomes an immutable government service, with Elon Musk appointed as its controller. This is due to how some people in this thread, myself included, believe laws can simply be ignored if you're a faggot leftist and have committed general crime. X will be used to expose these people. Every week, there will be a post or set of posts talking about these injustices, and it will be upon X's userbase to decide which one gets talked about.
If the commie decides to acquiesce and admit to their crime before it reaches that stage, they get a lighter sentence. If X/Grok finds them guilty, they are put to death with the details of their crime widely publicized. That simple.
Finally, we annex Cuba and the Bahamas in the interest of protecting US waters. Anyone who lost property during the commie revolution gets fully recompensated with inflation and interest, and anyone found to have benefitted from the commie regime gets punished.