The Supreme Court hearing Tuesday on the controversial federal health care law will be one for the history books.

After presumably clearing away a technicality which was the focus of the in-the-weeds opening day, the justices are getting down to the indisputable linchpin of the entire health law challenge and the matter that will most likely end up making legal history.

The so-called individual mandate is now under scrutiny, as the Supreme Court launched into its hearing Tuesday morning.

Though the ruling likely won't be issued for months, both sides of the argument descended on Washington for this day. At issue is the provision in the law requiring Americans to buy health insurance. And it could unravel President Obama's biggest domestic policy achievement if it's struck down...