The 11th Amendment is referenced in this decision only because the minority has to establish that the 11th Amendment itself doesn’t provide support for the position of the majority. But, as the majority cogently point out, they aren’t resting their decision on the 11th Amendment. Therefor, the references to the amendment in the opinions fall into two categories: comparison for the purpose of drawing analogy, or trolling with red herring. Hell, even the person writing the headnotes understood that.
To address the question posited by december, the significance has to do with how you view the role of the national government in the federal scheme. While barbitu8 and others in coastal waters might have considered the outcome important, as often happens in constitutional cases it is the rationale which has more significance to most of the country.
Government philosophy in this country runs in cycles. There are macro cycles that take 50-75 years to run their course, within which there occur shorter mini-cycles of varying lengths. Currently, we appear to be struggling to see what will happen when the macro-cycle which began in the '30s with the massive centralization of power in response to the Depression runs its course. This centralized power cycle has been mirrored by the homogenization of society across America, resulting in a change from individual states having easily definable individual characters to most of our society being much the same regardless of which state you are in. National food chains, grocery stores, clothing stores, movie theaters, radio companies, you name it, pretty much coast to coast you see and hear the same things everywhere. This sort of homogenization across state boundaries is made possible in large part by the increasing reliance upon the national government in Washington, D. C. to be the setters of standards and makers of laws.
The Rooseveltian Democracy is reaching the end of its days. Its demise has been foretold for some years now by the increasing gains made by the conservatives at the national and state levels, though you’ll notice how quickly Republicans at the national level are willing to be strong federalists when it suits their needs on issues important to them. The argument in the Supreme Court, exemplified by this decision and the fight over “sovereign immunity” is over where we go after this macro-cycle ends. The conservative wing wants to see states regain some control over their territories and cultures; the liberal wing wants to preserve the concept of a strong national government able to redress wrongs perpetuated by local level governments against national interests.
One way that the national government has attempted to keep a strong check on local “abuses” in an era of shrinking governemental resources is to empower individuals to act on its behalf. Combined with the delegation of quasi-judicial functions to administrative agencies, this allows the Congress to create strong rules, empower a watchdog agency, and have those rules enforced, all without clogging the national courts with cases or spending gobs of money on enforcement officials. It is this practice that is under attack by the conservative wing of the Supreme Court. The effect of the decision is to require that the agency in question, the FMC, act themselves to correct improper behaviour by individual states, rather than letting the FMC delegate that authority to individual citizens. The gamble by conservatives is that this will eventually result in states regaining some measure of local control, as the national government finds it impossible to assert strong control over all the areas it wants to regulate.
How important is this to you? I suppose that depends on how important you view the result of this power struggle between Washington, D. C. and the states. But one measure of how important you might want to view it comes from the fact that the minority in this decision has forced the Court to consider this specific issue five times in six years, and shows no signs of letting up the pressure on the majority. Given the relatively few numbers of cases granted certiorari each year, it is pretty obvious that the minority thinks it vital to force the majority to recant its basic position set forth in Seminole Tribe.