I was wrong because the federal court did not strike down Utah Code Ann. § 76-7-101 (2013), which the court defines as the capital 's' "Statute." The court struck down the 'cohabitation prong' of the Statute ("[t]he court finds the cohabitation prong of the Statute unconstitutional on numerous grounds and strikes it," p. 90 of the Decision").
Then, "to save the Statute," the court announced that "marry” and “purports to marry” in the Statute will now mean "bigamy in the literal sense . . . the . . . impermissible possession of two purportedly valid marriage licenses for the purpose of entering into more than one purportedly legal marriage" (pp. 90-91 of the Decision.)
As a result both cohabitation by a married person with someone other than his or her lawfully wedded spouse, and polygamous arrangements such as Kody Brown's, are no longer 'bigamy' in Utah because Mr. Brown has in not in possession of purportedly valid marriage licenses for his second, third, and fourth 'marriages.'
As for you, please read the court's conclusion at pp. 90-91. The court did not overturn a 'different law.' If you believe that is the case then I would appreciate it if you could educate me. In addition, I did not find that the court took no steps to prevent or prohibit unofficial marriages 'beyond the first one,' as you stated. I found the contrary. Second and later 'marriages' no longer constitute bigamy unless the purported bigamist is in "impermissible possession of two purportedly valid marriage licenses for the purpose of entering into more than one purportedly legal marriage."
SUMMARY: The court struck down the cohabitation prong of Utah's bigamy statute as unconstitutional, but left the statute in place as written by assigning a new definition to the word "marry" and the phrase "purports to marry" in the bigamy statute. A polygamist in Utah is no longer a bigamist unless he or she is in "impermissible possession of two purportedly valid marriage licenses for the purpose of entering into more than one purportedly legal marriage." A person who cohabitates with one or more persons is also not a bigamist unless he or she meets the marriage license requirement.
I stand corrected. Really though, whether it was a separate law, or a part of the bigamy law is a distinction without a difference in practical terms. My main point is that polygamy as it's generally referred to is still illegal. Much of the reporting, especially the headlines, is misleading about that, as shown by the comments on these threads.