Utopia, you are standing in it!

The decriminalisation of marijuana possession by American states doesn’t really matter that much because it is still illegal under Federal law. Marijuana markets moved into the open in the states that decriminalised it because the federal authorities have chosen not to enforce their laws against these traders.

Justice Clarence Thomas is a radical view of the interstate commerce clause. This clause of the US Constitution at the height of the new deal was reinterpreted to allow Congress to regulate both interstate commerce and intrastate markets that affected interstate commerce.

The current interpretation of this clause supported by everyone on the US Supreme Court but Thomas is Congress can regulate the possession of marijuana because this affects interstate commerce. Justice Scalia explains:

…the Commerce Clause permits congressional regulation of three categories:

(1) the channels of interstate commerce;

(2) the instrumentalities of interstate commerce, and persons or things in interstate commerce; and

(3) activities that "substantially affect" interstate commerce.

As …the Court affirms today, Congress may regulate noneconomic intrastate activities only where the failure to do so "could … undercut" its regulation of interstate commerce.

… This is not a power that threatens to obliterate the line between "what is truly national and what is truly local.

Justice Thomas rejects this view and wants to return to the original meaning of the interstate commerce clause:

Respondent’s local cultivation and consumption of marijuana is not "Commerce … among the several States."

Certainly no evidence from the founding suggests that "commerce" included the mere possession of a good or some personal activity that did not involve trade or exchange for value.

In the early days of the Republic, it would have been unthinkable that Congress could prohibit the local cultivation, possession, and consumption of marijuana

and

If the Federal Government can regulate growing a half-dozen cannabis plants for personal consumption (not because it is interstate commerce, but because it is inextricably bound up with interstate commerce), then Congress’ Article I powers – as expanded by the Necessary and Proper Clause – have no meaningful limits.

and further:

If the majority is to be taken seriously, the Federal Government may now regulate quilting bees, clothes drives, and potluck suppers throughout the 50 States.

This makes a mockery of Madison’s assurance to the people of New York that the "powers delegated" to the Federal Government are "few and defined", while those of the States are "numerous and indefinite."

In closing, Thomas said:

The majority prevents States like California from devising drug policies that they have concluded provide much-needed respite to the seriously ill.

Our federalist system, properly understood, allows California and a growing number of other States to decide for themselves how to safeguard the health and welfare of their citizens.

The adoption of the view of Thomas could not be more unlikely. Most federal regulation in the United States is based on linking it to the power of the Congress to regulate interstate commerce and foreign commerce. Thomas once noted that:

[w]hen asked at oral argument if there were any limits to the Commerce Clause, the Government was at a loss for words

The decriminalisation of marijuana in the United States will have to be based on more and more states choosing to decriminalise in the hope that the Federal Government does not enforce its rather savage criminal laws on drugs in their state. That’s is what seems to be happening. Whether that will still happen when a Republican wins the White House in 2016 remains to be seen.

Three American States have even passed hopelessly unconstitutional right to try laws. These laws  purport to allow the residents try experimental drugs that have not yet received approval of the Federal level by the FDA.

Even under the narrow interpretation of federal powers by Justice Thomas, these laws are unconstitutional. These laws nonetheless have social value because they are push the boundaries of the current political sense consensus.

This  evaluation applies to marijuana decriminalisation laws too.  They test the  current boundaries and can create the possibility of social change through democratic action.

Many who want a strong central government forget that the social agendas of the crazies to the left and right of them will also be implemented all in good time at the national level as well. Power rotates in any democracy so with enough time the meddlesome preferences of most sides of politics will be legislated into law so that everyone ends up been annoyed and over-regulated and more than a few end up before the courts and even in prison.

A wiser course in constitutional design is to give the parliament as much powers as you might wish those wreckers  and crazies that make up your political opponents to have when they come to office, as they surely must in six or nine years time. Even the British Labour Party took an interest in devolution and an assembly for London after 15 years of Maggie Thatcher, good and hard.