Are there limitations to federal law?

Many lawyers get paid millions of dollars fighting over this exact question. However, according to some interpretations of the Tenth Amendment, the states reserve all rights not explicitly granted to the feds.

Of course, some states try to use this to make an end-run around federal (or international) laws, which is where the real fun starts and the shocking headlines appear.

It is not uncommon for the federal government to pretend to give states choices, but if the preferred choice is not followed the federal government will withhold funding. The legal age for drinking is a good example of this. Federal law prohibits purchase of alcohol for anyone under 21, but allows states to set the legal age of consumption. For those states choosing to uphold this age for consumption as well, the federal government adds 10% funding for roads and transportation.
It’s a limit, but not really.

Whatever is not expressly denoted as federally controlled, is reserved by the states to legislate. That is the way the government was established. However, there are always fights about where that line is.

@janbb However, there are always fights about where that line is. The largest fight like that was called the Civil War.

@Yetanotheruser True!

What @jerv said.

Also, most federal power to regulate state affairs comes from the current expansive jurisprudence surrounding the U.S. Constitution’s commerce clause, which may or may not violate the spirit of the clause (I personally don’t think it violates the letter of the law here). In at least one case, SCOTUS decided any impact on the market impacts interstate commerce, even if the transaction took place entirely within a state.

But there are lots of broad powers granted to the feds anyway: transportation, patents/copyright, money (I’m hesitant to say monetary policy), defense, foreign relations, etc.

And then there is this interesting doctrine:

http://en.wikipedia.org/wiki/Federal_preemption