Could Congress fix the Social Security short-fall be simply changing the law?

Yes

If Trump can cut our costs on foreign waste of money, cut here, cut there, why not build the wall and fund social security. We could probably do much, much better without a Democratic Party too. lol

Congress is the one; specifically democrats, who created the problem. The Carter Admin made it available to everyone regardless of citizenship status. Since then you get on it for both real and imagined problems.

Yes. They could raise the FICA tax and/or reduce benefits.

Certainly, but it is for sure that about half of the citizens will be unhappy. I would expect massive lawsuits.

Yes, raise or get rid of the cap where earnings are taxed which is around $130,000.

So, Hey, Why Not Just Remove The Social Security Earnings Cap?

Eliminating " refugees " claims to Social Security benefits they never paid into would certainly take a load off the system .

yes. just get rid of the limit.