Re: why is polygamy illegal?
I already did. And no the laws do not change. The classifications change. Big difference. Ask any lawyer.
And the answer is the same as the one you quoted.
The rules do not change due to your relationship status, regardless if you are married to 1 person, single, divorced or a widow. The law applies to all equally. You file for immigration, apply, go through the review and the government decides.
Your fundamental rights remain the same.