@Pandora “I just looked up if the Supreme Court is the final word on the law of the land and found out that the Legislative Branch can re-write any law and change it.”
As @Call_Me_Jay has already pointed out, it isn’t quite this simple. In order to overturn a Supreme Court decision, Congress would have to propose an amendment to the US Constitution and the states would have to ratify it. This requires a two-thirds majority in both the House of Representatives (i.e., 290 “yea” votes) and the Senate (i.e., 67 “yea” votes) and a three-fourths majority of the states (i.e., 38 “yea” votes).
Technically, there is also an option where the states can begin the proposal process by getting two-thirds of the state legislatures to call for a constitutional convention. This has never happened, however, and is more likely to happen due to a conflict between state and federal governments than due to a conflict between Congress and the Supreme Court.
@Tropical_Willie “Trump can’t be prosecuted. Why is that?”
We actually do not know whether or not a sitting president can be prosecuted. There are conflicting legal theories, and it has never been tested in court. For obvious reasons, the Trump administration (along with basically every presidential administration in US history for whom the issue arose) holds to the theory that a sitting president cannot be prosecuted. In fact, they go further and say that he cannot even be indicted.
The argument is largely centered on Article I, Section 3, Clause 7 of the US Constitution:
“Judgment in Cases of Impeachment shall not extend further than to removal from Office, and disqualification to hold and enjoy any Office of honor, Trust or Profit under the United States: but the Party convicted shall nevertheless be liable and subject to Indictment, Trial, Judgment and Punishment, according to Law.”
Specifically, it’s the “but the Party convicted shall nevertheless be liable and subject to Indictment, Trial, Judgment and Punishment, according to Law” part that’s at issue. Those who say that a sitting president cannot be prosecuted argue that “the Party convicted” means that a sitting president must be impeached in the House and convicted by the Senate before they can be “liable and subject to Indictment, Trial, Judgment and Punishment, according to Law.”
Those who think that a sitting president can be prosecuted argue that “shall nevertheless be liable and subject to” is the relevant part of the clause, and that referring to “the Party convicted” is just a way of affirming that impeachment in the House and conviction by the Senate is not a substitute for civil and/or criminal liability. In support of this, they point to the fact that Article I, Section 3, Clause 7 is not just about the president (Senators and Representatives can be impeached and convicted, too), and that Senators and Representatives are not shielded from indictment or prosecution while in office.
One last complication: the US Department of Justice—under whose authority Mueller operates—has long been of the opinion that a sitting president cannot be indicted or prosecuted. The Office of Legal Counsel reached this conclusion in 1973 and reaffirmed it in 2000 (relevant source document). But this conclusion is based largely on the interpretation of Clause 7 by Alexander Hamilton (who is the origin of the claim that “the convicted Party” means indictment and prosecution cannot occur until after impeachment and conviction) as presented in The Federalist Papers (which are illuminating, but not legally binding).
But while this is the official position of the Department of Justice, nothing actually prevents Mueller from attempting to indict President Trump and sparking a protracted legal battle. The Office of Legal Counsel’s conclusion is an opinion, and whether or not that opinion is correct is a matter for the courts (or in this case, the US Supreme Court).