Illinois is now considering a medical marijuana law. And our state senate just passed a law granting drivers' licenses for illegal immigrants.
Neither of these will make it exactly legal to smoke weed or overstay your visa in Illinois. Because federal laws presumably still apply here.
I'm unclear on whether the state can actually stop a local cop from enforcing a federal law. But I bet they can discourage it.
If... due to a medical condition,
duly certified by a physician...
you need to get high,
it'll be mostly the DEA and FBI
that concern you.
The local fuzz won't burn you.