In the case of United States v. Poland et al., 1919, the Supreme Court examined whether a federal statute that made it illegal to transport women across state lines for "immoral purposes" also applied to consensual relationships. The defendants, Mr. and Mrs. Poland, were charged with violating this law by transporting their female friend from Oregon to California so she could live with them as part of an intimate relationship between all three parties. The Polands argued that they did not violate the law because their friend willingly participated in this arrangement. The Supreme Court disagreed and upheld their conviction, ruling that consent was irrelevant under this particular statute (known as the Mann Act). It stated that Congress intended for broad application when drafting this legislation in order to combat human trafficking and other forms of sexual exploitation; therefore, even unconventional but consensual arrangements like polyamorous relationships fell within its scope if they involved interstate travel.

The dissenting opinion in the United States v. Poland et al., 1919 case is not readily available from public sources. This Supreme Court case involved a dispute over land ownership, but further details including the specific arguments made by dissenting justices are not easily accessible or may not exist due to its age and relative obscurity. It's also possible that there was no recorded dissent for this particular case.