[pessimizer]

Other countries don't institutionalize the two-party system by law. Because it would be insane and antidemocratic to create a complicated network of laws that would have to be eliminated state by state in order to ordain that an entire country must be ruled by two intimately-linked private clubs in turn.

[cryptonector]

The two-party system isn't so heavily institutionalized "by law". The law generally gives advantages to parties that pull in more than x% of the vote, and it so happens that the first-past-the-post system of electing representatives makes it very difficult for a third party to take root.

[int_19h]

Except our law is nothing like that. You can have a party take 45% of each district across the whole country and end up with zero seats in the House (because the other party took 55% of each).

[dartos]

The first past the post system is encoding a two party system into law. If it makes to hard enough for a third party to take hold, there might as well not be one.

Not everything is spelled in ink.

[bigstrat2003]

That's not "encoded into the law". The outcomes of the law are not the same as the law itself.

[dartos]

Practically speaking, they are.

The effect of a law is at least as important as the literal words on the page.