The law of the land in the United States is the Constitution, which is a written document, and further to the point, permits a specific process to amend the Constitution, for the Constitution as created, is in its construction, a vehicle created by the people and for the people. The Supreme Court is the highest law of the land, of which, if law and justice are to legitimately mean anything to the people of this country that law must be equally applied to all people in a fair manner, rightly applied, and that is consistent with the Constitution.
In point of fact, when it comes to Supreme Court decisions, too many of those decision, do not take into consideration the Constitution as it is, but rather, begin from an individual partisan standpoint of the judge, of which, their objective is to decide the case, on no other merit, than their own wishes of what they so wish the Constitution should have said, or kind of says, or might just say. This kind of judicial activism is not appropriate for the judicial branch to begin with, for rather to change law, is the domain of the legislature branch and not to be breached by the judicial branch. Further to the point, when Supreme Court decisions are based on the individual preferences of the judges and their ideological or political viewpoints, the Supreme Court, as an institution, has no real legitimacy, no moral authority, and is inimical to the Constitution.
Today's Supreme Court, clearly makes partisan decisions, so that, as reported by slate.com, "For almost 200 years, from the Founding through the Burger Court, the Supreme Court struck down federal statutes by a one-vote majority only 24 times. Since then, the court has lost the instinct for restraint in this domain: The Rehnquist Court used 5-4 votes to strike down 20 federal laws in 19 years from 1986 to 2005." This, quite clearly states the obvious, which most pundits and informed citizens are quite aware of, that this Supreme Court is partisan, and the decisions that this Supreme Court renders are far too often done upon partisan lines.
If, Supreme Court decisions did not have a real material impact on the people of America, than it would not be the controversy that it is so today. But, rather, each of the following recent decisions were all 5-4 votes with meaningful material impact upon American citizens, for instance: Bush v. Gore, 2000--the Presidential election; Citizens United v. Federal Election Commission, 2010--unlimited campaign spending; National Federation of Independent Business v. Sebelius, 2012--Affordable Care Act; Shelby County v. Holder, 2013--voting laws; and Obergefell v. Hodges, 2015--same sex marriage. Each of these cases was decided by one vote on the Supreme Court and thereby became the law, or the interpretation of law for the Federal government as applicable to all its citizens.
The degree of partisanship on the Supreme Court is not going to go away anytime soon, so then, the question should be asked as to whether a mere majority of the Supreme Court should be allowed to effectively make or interpret law, of which, all citizens and their representatives must so accept it. One way to effectively reduce the impact of partisanship on the Supreme Court is to invalidate 5-4 majorities as being sufficient in and of itself in order to thereby make new law or to overturn law, but instead to mandate that decisions must be instead a supermajority of 6-3 or even possibly 7-2. That is to say, when four Supreme Court justices have their voice effectively silenced, are we to take it, that their dissent should be seen as effectively being of no intrinsic worth or merit?